12.11B: Localization of Pain
Localization of pain is determined by whether the pain is superficial somatic, visceral, or deep somatic.
- Describe the localization of pain in the peripheral nervous system
Key Points
- Nociceptive pain is caused by stimulation of peripheral nerve fibers that respond only to stimuli approaching or exceeding harmful intensity ( nociceptors ).
- Nociceptive pain may be classified according to the mode of noxious stimulation, the most common categories being thermal (heat or cold), mechanical (crushing, tearing, etc.), and chemical (iodine in a cut, chili powder in the eyes).
- Superficial pain is initiated by activation of nociceptors in the skin or other superficial tissue, and is sharp, well-defined, and clearly located.

- Deep somatic pain is initiated by stimulation of nociceptors in ligaments, tendons, bones, blood vessels, fasciae and muscles, and is dull, aching, poorly localized pain.
- Referred pain is characterized by pain felt in a location away from the site of the painful stimulus.
Key Terms
- visceral pain : Visceral pain is diffuse, difficult to locate, and often referred to a distant, usually superficial, structure. It may be accompanied by nausea and vomiting and may be described as sickening, deep, squeezing, and dull.
- deep somatic pain : Pain initiated by stimulation of nociceptors in ligaments, tendons, bones, blood vessels, fasciae and muscles; it is dull, aching, poorly localized pain. Examples include sprains and broken bones.
- superficial somatic pain : Pain initiated by activation of nociceptors in the skin or other superficial tissue; it is sharp, well-defined, and clearly located. Examples of injuries that produce superficial somatic pain include minor wounds and minor (first degree) burns.
Pain Categories
Nociceptive pain is caused by stimulation of peripheral nerve fibers that respond only to stimuli approaching or exceeding harmful intensity (nociceptors), and may be classified according to the mode of noxious stimulation.
The most common categories are thermal (heat or cold), mechanical (crushing, tearing, etc.), and chemical (iodine in a cut, chili powder in the eyes). Nociceptive pain may also be divided into visceral, deep somatic, and superficial somatic pain.
Visceral Pain
Visceral structures are highly sensitive to stretch, ischemia, and inflammation, but relatively insensitive to other stimuli that normally evoke pain in other structures, such as burning and cutting. Visceral pain is diffuse, difficult to locate, and often referred to a distant, usually superficial, structure. It may be accompanied by nausea and vomiting and may be described as sickening, deep, squeezing, and dull.
Deep Somatic Pain
Deep somatic pain is initiated by the stimulation of nociceptors in ligaments, tendons, bones, blood vessels, fasciae, and muscles, and is a dull, aching, poorly localized pain. Examples include sprains and broken bones. Superficial pain is initiated by activation of nociceptors in the skin or other superficial tissue, and is sharp, well-defined, and clearly located. Examples of injuries that produce superficial somatic pain include minor wounds and minor (first degree) burns.
Referred Pain
Referred pain (also reflective pain) is pain perceived at a location other than the site of the painful stimulus. An example is the case of ischemia brought on by a myocardial infarction ( heart attack), where pain is often felt in the neck, shoulders, and back rather than in the chest, the site of the injury.
The International Association for the Study of Pain has not officially defined referred pain as of 2001; hence, several authors have defined the term differently. Radiation is different from referred pain.
The pain related to a myocardial infarction could either be referred pain or pain radiating from the chest. Classically, the pain associated with a myocardial infarction is located in the middle or left side of the chest, where the heart is actually located. The pain can radiate to the left side of the jaw and into the left arm.
Referred pain occurs when the pain is located away from or adjacent to the organ involved. An example would be when a person has pain only in their jaw or left arm, but not in the chest. The size of referred pain is related to the intensity and duration of ongoing/evoked pain.
Also, temporal summation is a potent mechanism for the generation of referred muscle pain. Central hyperexcitability is also important for the extent of referred pain.
Temporal summation : Temporal summation, shown in the diagram, is the transmitting of signals with increased frequency of impulse, thus increasing the strength of signals in each fiber. Temporal summation is a potent mechanism for the generation of referred muscle pain.
Brain freeze : In an ice cream headache, known colloquially as brain freeze and medically as a cold-stimulus headache, the trigeminal nerve, shown in yellow, conducts signals from dilating blood vessels in the palate to the brain that interpret the pain as coming from the forehead.
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4.3C: ABC Transporters
- Summarize the function of the three major ABC transporter categories: in prokaryotes, in gram-negative bacteria and the subgroup of ABC proteins
ATP-binding cassette transporters (ABC-transporters) are members of a protein superfamily that is one of the largest and most ancient families with representatives in all extant phyla from prokaryotes to humans. ABC transporters are transmembrane proteins that utilize the energy of adenosine triphosphate (ATP) hydrolysis to carry out certain biological processes including translocation of various substrates across membranes and non-transport-related processes such as translation of RNA and DNA repair. They transport a wide variety of substrates across extra- and intracellular membranes, including metabolic products, lipids and sterols, and drugs. Proteins are classified as ABC transporters based on the sequence and organization of their ATP-binding cassette (ABC) domain(s).
ABC transporters are involved in tumor resistance, cystic fibrosis and a range of other inherited human diseases along with both bacterial (prokaryotic) and eukaryotic (including human) development of resistance to multiple drugs. Bacterial ABC transporters are essential in cell viability, virulence, and pathogenicity.
ABC transporters are divided into three main functional categories. In prokaryotes, importers mediate the uptake of nutrients into the cell. The substrates that can be transported include ions, amino acids, peptides, sugars, and other molecules that are mostly hydrophilic. The membrane-spanning region of the ABC transporter protects hydrophilic substrates from the lipids of the membrane bilayer thus providing a pathway across the cell membrane. In gram-negative bacteria, exporters transport lipids and some polysaccharides from the cytoplasm to the periplasm. Eukaryotes do not possess any importers. Exporters or effluxers, which are both present in prokaryotes and eukaryotes, function as pumps that extrude toxins and drugs out of the cell. The third subgroup of ABC proteins do not function as transporters, but rather are involved in translation and DNA repair processes.
In bacterial efflux systems, certain substances that need to be extruded from the cell include surface components of the bacterial cell (e.g. capsular polysaccharides, lipopolysaccharides, and teichoic acid), proteins involved in bacterial pathogenesis (e.g. hemolysis, heme-binding protein, and alkaline protease), heme, hydrolytic enzymes, S-layer proteins, competence factors, toxins, antibiotics, bacteriocins, peptide antibiotics, drugs and siderophores. They also play important roles in biosynthetic pathways, including extracellular polysaccharide biosynthesis and cytochrome biogenesis.
Key Points
- ABC transporters use the energy of ATP hydrolysis to transport substrates across cell membranes.
- Bacterial ABC transporters are essential in cell viability, virulence, and pathogenicity.
- The substrates that can be transported include ions, amino acids, peptides, sugars, and other molecules that are mostly hydrophilic.
Key Terms
- membrane : A flexible enclosing or separating tissue forming a plane or film and separating two environments (usually in a plant or animal).
- hydrolysis : A chemical process of decomposition involving the splitting of a bond and the addition of the hydrogen cation and the hydroxide anion of water.
- ATP-binding cassette (ABC) domain : The ATP-binding cassette (ABC) family is a group of proteins which bind and hydrolyse ATP in order to transport substances across cellular membranes.


4.2: The SIFT Method
Mike Caulfield, Washington State University digital literacy expert, has helpfully condensed key fact-checking strategies into a short list of four moves, or things to do to quickly make a decision about whether or not a source is worthy of your attention . It is referred to as the “SIFT” method:
Stop
When you initially encounter a source of information and start to read it— stop . Ask yourself whether you know and trust the author, publisher, publication, or website. If you don’t, use the other fact-checking moves that follow, to get a better sense of what you’re looking at. In other words, don’t read, share, or use the source in your research until you know what it is, and you can verify it is reliable.
This is a particularly important step, considering what we know about the attention economy —social media, news organizations, and other digital platforms purposely promote sensational, divisive, and outrage-inducing content that emotionally hijacks our attention in order to keep us “engaged” with their sites (clicking, liking, commenting, sharing). Stop and check your emotions before engaging!
Investigate the Source
You don’t have to do a three-hour investigation into a source before you engage with it. But if you’re reading a piece on economics, and the author is a Nobel prize-winning economist, that would be useful information. Likewise, if you’re watching a video on the many benefits of milk consumption, you would want to be aware if the video was produced by the dairy industry. This doesn’t mean the Nobel economist will always be right and that the dairy industry can’t ever be trusted. But knowing the expertise and agenda of the person who created the source is crucial to your interpretation of the information provided.
When investigating a source, fact-checkers read “laterally” across many websites, rather than digging deep (reading “vertically”) into the one source they are evaluating. That is, they don’t spend much time on the source itself, but instead they quickly get off the page and see what others have said about the source. They open up many tabs in their browser, piecing together different bits of information from across the web to get a better picture of the source they’re investigating.
Please watch the following short video [2:44] for a demonstration of this strategy. Pay particular attention to how Wikipedia can be used to quickly get useful information about publications, organizations, and authors.
Note: Turn on closed captions with the “CC” button or use the text transcript if you prefer to read.
Find Better Coverage
What if the source you find is low-quality, or you can’t determine if it is reliable or not? Perhaps you don’t really care about the source—you care about the claim that source is making . You want to know if it is true or false. You want to know if it represents a consensus viewpoint, or if it is the subject of much disagreement. A common example of this is a meme you might encounter on social media. The random person or group who posted the meme may be less important than the quote or claim the meme makes.
Your best strategy in this case might actually be to find a better source altogether , to look for other coverage that includes trusted reporting or analysis on that same claim. Rather than relying on the source that you initially found, you can trade up for a higher quality source.
The point is that you’re not wedded to using that initial source. We have the internet! You can go out and find a better source, and invest your time there. Please watch this video [4:10] that demonstrates this strategy and notes how fact-checkers build a library of trusted sources they can rely on to provide better coverage.
Note: Turn on closed captions with the “CC” button or use the text transcript if you prefer to read.
Trace Claims, Quotes, and Media to the Original Context
Much of what we find on the internet has been stripped of context. Maybe there’s a video of a fight between two people with Person A as the aggressor. But what happened before that? What was clipped out of the video and what stayed in? Maybe there’s a picture that seems real but the caption could be misleading. Maybe a claim is made about a new medical treatment based on a research finding—but you’re not certain if the cited research paper actually said that. The people who re-report these stories either get things wrong by mistake, or, in some cases, they are intentionally misleading us.
In these cases you will want to trace the claim, quote, or media back to the source, so you can see it in its original context and get a sense of whether the version you saw was accurately presented. Please watch the following video [1:33] that discusses re-reporting vs. original reporting and demonstrates a quick tip: going “upstream” to find the original reporting source.
Note: Turn on closed captions with the “CC” button or use the text transcript if you prefer to read.
Sources
“ Online Verification Skills – Video 2: Investigate the Source .” YouTube , uploaded by CTRL-F, 29 June 2018.
“ Online Verification Skills – Video 3: Find the Original Source .” YouTube , uploaded by CTRL-F, 25 May 2018.
“ Online Verification Skills – Video 4: Look for Trusted Work .” YouTube , uploaded by CTRL-F, 25 May 2018.
SIFT text adapted from “ Check, Please! Starter Course ,” licensed under CC BY 4.0
SIFT text and graphics adapted from “ SIFT (The Four Moves) ” by Mike Caulfield, licensed under CC BY 4.0


6.2: Functional Disorders
By the end of this section, you will be able to:
- Explain the different disorders, treatment, and nursing interventions affecting menstruation
- Explain the disorders, treatment, and nursing interventions associated with menopause
- Describe the pathophysiology, symptoms, treatment, and nursing interventions associated with polycystic ovary syndrome (PCOS)
- Describe the symptoms, treatment, and nursing interventions associated with endometriosis
- Explain the risk factors, treatment, and patient education associated with chronic pelvic pain
This module focuses on key functional reproductive health disorders that can affect any person AFAB at some point in their life. The underlying mechanisms, clinical manifestations, diagnostic approaches, and evidence-based medical and nursing interventions for these conditions will be discussed. Menstrual abnormalities, the transitional phases of perimenopause and menopause, the complexities of endometriosis and polycystic ovary syndrome (PCOS), and the multidimensional aspects of chronic pelvic pain will also be reviewed. Nurses provide education on these conditions and how they relate to their patients’ pain. Nurses also provide holistic care and support to persons experiencing functional reproductive health issues.
Menstrual Disorders
The average age for menarche in the United States is approximately 12 years of age (Gruber & Modan-Moses, 2021). A normal menstrual cycle is approximately 21 to 34 days in length, with the menses lasting less than 7 days (American College of Obstetricians and Gynecologists [ACOG], 2015). Abnormal menstrual cycles can occur for many reasons. Understanding menstrual disorders is important, as these disorders can significantly impact a person’s physical and emotional well-being. Menstrual disorders encompass a wide range of conditions that affect the regularity, intensity, and duration of the menstrual cycle. From heavy or prolonged menstrual bleeding to irregular or absent periods, these disorders can present complex challenges for both patients and health-care providers.
Amenorrhea
The absence of menstruation in people who have ovaries and a uterus, who are of reproductive age, is called amenorrhea. There are two types of amenorrhea: primary and secondary amenorrhea. The absence of menarche by the age of 16 years is called primary amenorrhea , and the absence of menstruation for a duration of three or more consecutive cycles in people who reported previously experiencing regular menstrual cycles secondary amenorrhea (Nawaz & Rogol, 2022). Table 6.1 lists the most common causes of primary and secondary amenorrhea.
| Primary Amenorrhea | Secondary Amenorrhea |
|---|---|
|
|
In addition to the absence of menstrual bleeding, common signs and symptoms associated with amenorrhea may include signs of underlying hormonal imbalances, such as:
- hirsutism (excessive hair growth on unexpected areas)
- hair loss
- headache
- galactorrhea (milk production not related to pregnancy or breast-feeding)
- visual changes
Care of the patient with amenorrhea starts with a detailed history and physical examination, with the provider first determining whether the patient has primary or secondary amenorrhea. If primary amenorrhea is confirmed, the provider will assess for chromosomal abnormalities. If the patient has secondary amenorrhea, the nurse will ask focused assessment questions about menstrual and reproductive history and symptoms of hormonal changes. Diagnostic testing will vary depending on the suspected etiology and may include hormone-level assessments, such as:
- beta–human chorionic gonadotropin (beta-hCG) to rule out pregnancy;
- testosterone and dehydroepiandrosterone sulfate ( DHEAS ) to look for hyperandrogenism ;
- follicle-stimulating hormone ( FSH ), luteinizing hormone (LH) , estrogen , thyroid function , and prolactin, to evaluate for hormonal imbalances;
- imaging tests, such as pelvic ultrasound or computed tomography (CT) , to evaluate the patient for adrenal tumors, pituitary tumor s, anatomic variants (transverse vaginal septum or absence of ovaries, uterus, or cervix); and
- karyotyping (Nawaz & Rogol, 2022).
Treatment of amenorrhea focuses on addressing the underlying cause. Medical management can include hormonal therapies such as combined oral contraceptive s or progestin therapy to induce withdrawal bleeding, regulate menstrual cycles, and correct hormonal imbalances. For specific medical causes of amenorrhea like hyperprolactinemia , targeted medications like dopamine agonist s may be used (Nawaz & Rogol, 2022). Patients with ongoing amenorrhea, particularly those with hypothalamic amenorrhea, may be at risk for osteoporosis due to bone loss associated with estrogen deficiency. Hypothalamic amenorrhea can be caused by weight loss, stress, or increased physical exercise. Some patients may require bone density monitoring or treatment with bisphosphonate s to reduce bone loss; patients not desiring pregnancy will improve bone loss by taking estrogen and progesterone (Altayar et al., 2017).
Nonpharmacologic approaches to managing amenorrhea include lifestyle modification s, such as maintaining a healthy weight, managing stress levels, and ensuring adequate nutrition and exercise (Nawaz & Rogol, 2022). For persons with eating disorders or excessive exercise-induced amenorrhea, a multidisciplinary approach involving dieticians, therapists, and exercise specialists is crucial (Nawaz & Rogol, 2022).
Nurses play a vital role in the care of persons with amenorrhea. They should prioritize patient education, explaining the etiology and treatment options, as well as discussing potential long-term implications such as infertility or bone health concerns. Nurses can offer emotional support, addressing any concerns or anxieties related to the condition. They should also collaborate with other health-care providers to ensure comprehensive care, monitor treatment responses, and assess for potential complications or side effects of medications.
Dysmenorrhea
Painful menstruation that occurs in the absence of a physiologic cause is called dysmenorrhea.  The condition is further classified as either primary dysmenorrhea , which is typical menstrual pain that occurs before or during a period, or secondary dysmenorrhea , which is menstrual pain caused by an underlying condition (ACOG, 2022a). Common signs and symptoms of dysmenorrhea include cramping abdominal pain that may radiate to the lower back and thighs, nausea, vomiting, fatigue, headache, and diarrhea (ACOG, 2022a). Dysmenorrhea is more prevalent in younger people, smokers, people with early menarche or a family history, and people who have never been pregnant or given birth (Hickey et al., 2023).
Evaluating a patient for dysmenorrhea starts with a thorough medical history and a physical exam. In most cases, diagnostic testing is warranted only when medication is not effective at managing menstrual pain. Pelvic ultrasound is a noninvasive option to visualize the pelvic anatomy. Other options may include hysteroscopy or laparoscopy to get a better view of the reproductive structures (ACOG, 2022a).
The goals of medical management are to alleviate pain and improve quality of life. Nonsteroidal anti-inflammatory drugs ( NSAIDs ), such as ibuprofen (Motrin) or naproxen (Aleve), are commonly used as first-line pharmacologic treatment to inhibit prostaglandin synthesis and reduce pain (Smith & Kaunitz, 2022). Hormonal therapies, such as combined oral contraceptives or progestins, may also be prescribed to reduce menstrual pain by suppressing ovulation and reducing endometrial proliferation (Smith & Kaunitz, 2022). If these medications do not sufficiently relieve pain, diagnostic laparoscopy can be considered if it has not already been performed. Other surgical procedures may include hysterectomy (removal of the uterus) or endometrial ablation (destruction of the endometrial lining). A hysterectomy is a major surgery that requires general anesthesia and significant time to heal. Endometrial ablation is performed in the office under sedation and does not require extended healing time. Both procedures are appropriate only in people no longer considering having children (Smith & Kaunitz, 2022).
Nonpharmacologic approaches can complement medical treatment and include heat therapy (e.g., hot water bottle, warm bath), relaxation technique s (e.g., deep breathing, guided imagery), regular exercise, and dietary modifications (McKenna & Fogleman, 2021). Applying heat to the lower abdomen can help relax uterine muscles and reduce pain, and relaxation techniques can help manage stress and promote overall well-being. Many people also report that the use of acupuncture and transcutaneous electric nerve stimulation (TENS) are helpful in reducing dysmenorrhea (ACOG, 2022a; and Smith & Kaunitz, 2022).
Nurses play a crucial role in managing dysmenorrhea. Nursing activities for the patient with dysmenorrhea may include:
- providing education about the condition, including its causes, common symptoms, and available treatment options
- assessing pain levels, using validated pain scales, and monitoring the effectiveness of interventions
- providing emotional support and addressing any anxiety or distress associated with dysmenorrhea
- encouraging self-care practices, such as heat therapy, relaxation techniques, and exercise
Evaluate Outcomes
Nurses provide a great deal of education for patients with dysmenorrhea. In order to evaluate the success of the education, nurses must consider evaluation outcomes.
The nurse provides education on nonpharmacologic pain relief. To evaluate the outcomes, the nurse can ask the following questions:
- What relaxation technique would work best for you?
- What kind of exercise could you do during your period?
- Can you think of ways to relax your uterus?
- Do you remember where to apply the TENS pads?
By asking these questions, the nurse can determine if the education was successful or if further education is warranted.
Premenstrual Syndrome
The common, cyclic, and multifaceted disorder that occurs during the luteal phase of the menstrual cycle in people who menstruate is called premenstrual syndrome (PMS) . It typically occurs 1 to 2 weeks before menstruation and is characterized by a combination of physical, emotional, and behavioral symptoms that significantly impact a person’s daily life and functioning (U.S. Department of Health and Human Services [HHS] Office on Women’s Health, 2021b)., 2021b). A rare type of PMS is premenstrual dysphoric disorder (PMDD) , which is similar to PMS but has a more extreme presentation, causing extreme depression and anxiety in the luteal phase of the cycle (Mishra et al., 2021).
The signs and symptoms of PMS can vary widely among people but commonly include mood swings, irritability, anxiety, fatigue, breast tenderness, bloating, and changes in appetite or sleep patterns (HHS Office on Women’s Health, 2021b). Emotional symptoms can include feelings of sadness, tension, or difficulty in concentrating, while physical symptoms may manifest as headache, joint or muscle pain, and gastrointestinal disturbances (HHS Office on Women’s Health, 2021b). It is possible for people to have only physical symptoms, only emotional symptoms, or both. Symptoms may also change throughout a person’s reproductive lifespan.
PMS is primarily diagnosed based on the presence of characteristic symptoms during the luteal phase of the menstrual cycle. However, to establish a definitive diagnosis and rule out other underlying conditions, health-care providers should conduct a thorough medical history and evaluation of symptoms along with a thorough menstrual cycle history. Laboratory tests, such as thyroid function or complete blood count, may be performed to screen for other medical conditions such as hyper- or hypothyroidism and anemia (Casper, 2023).
The management of PMS often involves a multimodal approach. Pharmacologic interventions may be considered for severe cases and can include selective serotonin reuptake inhibitors (SSRIs) or hormonal contraceptives to regulate hormone levels and alleviate symptoms (HHS Office on Women’s Health, 2021b). Nonsteroidal anti-inflammatory drugs (NSAIDs) may be prescribed for pain relief, and diuretics can be used to help relieve bloating and water retention (HHS Office on Women’s Health, 2021b). Some people have found that certain supplements, particularly magnesium , vitamin B6 , calcium , and omega-3 fatty acids , may be effective in relieving symptoms (HHS Office on Women’s Health, 2021b). It is important for the nurse to discuss any potential interactions or side effects of these supplements.
Nonpharmacologic measures play a significant role in PMS management. Helpful lifestyle modification s may include:
- regular exercise
- cognitive behavioral therapy (CBT)
- a balanced diet rich in complex carbohydrates, decreased salt, and decreased refined sugars
- sleeping 7 to 8 hours each night
- stress-reduction techniques, such as relaxation exercises, journaling, and meditation (HHS Office on Women’s Health, 2021b)
Nurses play a vital role in caring for persons experiencing PMS. Assessment of symptoms, menstrual history, and psychosocial factors can aid in identifying the severity of the condition and its impact on the patient’s life. Nurses must also collaborate with health-care providers and advocate for their patients when necessary to develop personalized care plans that incorporate pharmacologic and nonpharmacologic interventions. Patient education on symptom management, healthy lifestyle practices, and coping strategies helps patients to better manage PMS and improve their quality of life.
Abnormal Uterine Bleeding
The common gynecologic condition characterized by atypical bleeding patterns is called abnormal uterine bleeding (AUB) . It encompasses various menstrual irregularities, including heavy menstrual bleeding ( menorrhagia ), prolonged menstrual bleeding ( hypermenorrhea ), irregular menstrual cycles ( metrorrhagia ), bleeding or spotting after sex, irregular periods that vary in length by more than 7 to 9 days, menstrual cycles longer than 35 days or shorter than 21 days, intermenstrual bleeding (between periods), and bleeding after menopause (ACOG, 2023b).
There are two types of AUB: acute and chronic. Acute AUB is a sudden onset of abnormal bleeding that lasts for 2 hours or longer and requires treatment to prevent excessive blood loss and other complications (ACOG, 2023b; Davis & Sparzak, 2022). Chronic AUB is bleeding that deviates from the normal pattern and has occurred for the past 6 months.
Potential causes of AUB include:
- trauma
- ovulatory dysfunction
- neoplasms
- malignant lesions
- reproductive tract infections
- the presence of uterine fibroid s or polyps
- adenomyosis or endometriosis
- blood clotting disorders
- certain medications, such as hormonal birth control
- ectopic pregnancy or miscarriage
- pelvic inflammatory disease (PID) (ACOG, 2023b)
The hallmark sign of AUB is changes in menstrual bleeding patterns (Davis & Sparzak, 2022). People may experience excessively heavy or prolonged periods that require frequent tampon or pad changes, defined as more than once per hour (ACOG, 2023b). Other signs may include fatigue, anemia, and menstrual pain.
Diagnosing AUB begins with a comprehensive assessment of the patient’s medical history, menstrual patterns, and related symptoms. A physical examination, including pelvic examination, is essential to rule out other gynecologic conditions. Laboratory tests, such as complete blood count (CBC) to assess for anemia and thyroid function , can help identify potential underlying causes. A pregnancy test may be needed to rule out pregnancy as a potential cause for the bleeding. Imaging tests like transvaginal ultrasound , hysteroscopy , or sonohysterography may be performed to evaluate the uterine cavity, while endometrial biopsy can be used to test for endometrial hyperplasia in people at high risk (Davis & Sparzak, 2022). Postmenopausal patients with AUB are at high risk for endometrial hyperplasia and endometrial cancer . Therefore, any postmenopausal person who presents with uterine bleeding should be evaluated.
The management of AUB consists of identifying and addressing the underlying cause, alleviating symptoms, and improving the patient’s quality of life. In most cases, medical treatment is preferred to surgical options (Davis & Sparzak, 2022). Medical treatment options often include hormonal therapy , which helps to regulate menstrual cycles and reduce menstrual flow. In cases where AUB is caused by structural abnormalities like polyps or fibroid s, surgical interventions, like hysteroscopic polypectomy or myomectomy , or pharmacologic treatments, such as combined birth control pills, might be necessary.
Nonpharmacologic interventions are often recommended and can complement medical treatment to improve outcomes. Lifestyle modifications, such as regular exercise and a well-balanced diet, can promote hormonal balance and overall health. Managing stress and practicing relaxation technique s may also help reduce menstrual symptoms and restore regular menstrual patterns.
Nurses play a crucial role in providing comprehensive care to patients with AUB. A thorough assessment of the patient’s menstrual history, symptoms, and concerns can aid in identifying potential contributing factors and underlying causes. Nurses can educate patients about AUB, its potential impact on health, and the importance of seeking timely medical attention. Patient education on the appropriate use of prescribed medications, potential side effects, and expected outcomes is vital. Nurses can also assist in coordinating further diagnostic tests, providing pre- and postprocedural care, and ensuring patients understand treatment plans. Empowering patients to track their menstrual cycles and symptoms using calendars or apps can facilitate better communication with health-care providers.
Perimenopause and Menopause
The phase of menstrual irregularities called perimenopause is attributed to fluctuating hormone levels that last for months up to several years and ends when menses has ceased for 12 months (North American Menopause Society, n.d.-a; Smuskiewicz, 2019). Twelve months of amenorrhea is considered menopause, which represents the culmination of this transition (World Health Organization, 2022). Menopause typically occurs between ages 40 and 59, though the average age is 51 years old (North American Menopause Society, n.d.-a). In addition to the natural transition that occurs with advancing age, menopause can also occur in some patients due to surgical removal of the ovaries or some medications that affect ovarian or hormonal function, or chemotherapy and radiation therapy to the reproductive organs (North American Menopause Society, n.d.-a). People who undergo induced menopause have the same signs and symptoms as people who go through this transition naturally.
Menopause and Perimenopause
Perimenopause and menopause are very much cultural phenomena (Women’s Health Network, 2023).
Japan
The concept of “hot flashes” is relatively new in Japan. This could be due to the high-soy diet of Japanese persons AFAB. Fewer people in Japan report having hot flashes and other vasomotor symptoms than people in the West (Rei Otsuka et al., 2020). In fact, the word for menopause in Japanese translates to “a period of renewal and regeneration” (Women’s Health Network, 2023).
Mayan Descendants
Descendants of the ancient Mayan civilization still live in pockets of rural Guatemala and Mexico and have been interviewed about their view of menopause. Many said they do not experience any of the typical menopausal symptoms (such as hot flashes and insomnia), despite having FSH levels similar to those of Western people (Women’s Health Network, 2023). In addition, many of these Mayan people look forward to this transition to the next stage in their life (Women’s Health Network, 2023). These differences could be explained by diet and other health-related behaviors; attitudes about aging and perceptions about age may play a major role (Marloff, 2021).
Western Society
Western societies often revere youth and attractiveness, leading to differing views on aging and menopause (Marloff, 2021; Women’s Health Network, 2023).
Changes in Menstruation
Changes in menstruation are often the hallmark of perimenopause and can vary significantly among people. During perimenopause, the ovaries start making less estrogen and progesterone , which can cause anovulation and missed periods (ACOG, 2022b). See Chapter 4 Influences on Fertility for a review of reproductive hormones and the menstrual cycle. These changing hormones can cause cycles to become longer or shorter, menstrual flow to be heavier or lighter, or bleeding/spotting to occur between periods (Eisenberg, 2022). It is not unusual for people in perimenopause to skip periods for several months and then resume a regular pattern of menstruation.
Vasomotor Symptoms
More commonly known as hot flashes and night sweats, vasomotor symptoms (VMS) are cardinal symptoms of perimenopause and menopause. These episodes of sudden and intense heat are accompanied by skin flushing, perspiration, palpitations, and an acute feeling of discomfort and can last for several minutes (World Health Organization, 2022). Vasomotor symptoms often disturb sleep patterns and impact daily activities, making their management crucial for people experiencing this transition. Hot flashes that occur at night are known as night flushes or night sweats and can lead to insomnia and other sleep disturbances.
The pathophysiology of vasomotor symptoms is not well understood, but it is believed that persons experience a reduction in thermoregulation, which may be attributed to a reduction in several hypothalamic hormones and a narrowing of the thermoneutral zone (Jina et al., 2022). Although vasomotor symptoms have long been thought of as uncomfortable without a physiologic effect, growing research is showing that they may be associated with negative cardiovascular risk factors, including insulin resistance, diabetes , and hypertension (Jina et al., 2022). However, further research is needed to determine the actual clinical impact of VMS on cardiovascular health.
Vaginal Dryness
Declining estrogen levels during perimenopause and menopause can affect the vagina and external genitalia (the vulva). This reduction of estrogen weakens the vulvovaginal epithelium, causing it to be thinner and less elastic (The North American Menopause Society, n.d.-b). Lower estrogen levels can also cause a reduction in lubrication and an increase in vaginal pH (The North American Menopause Society, n.d.-b), This can result in discomfort, pain during intercourse (dyspareunia), and increased vulnerability to infections.
 The nurse should advise patients to continue having regular sexual activity through menopause to help reduce vulvovaginal atrophy (thinning of the skin of the vulva and vagina) and to use lubrication during intercourse to reduce pain and injury to the vagina (The North American Menopause Society, n.d.-b).
Changes in Metabolism
Metabolic shifts occur as estrogen levels decline and androgen levels increase during perimenopause and menopause, making people more likely to gain weight, particularly around the abdomen, and muscle loss (Ko & Jung, 2021). These changes affect overall metabolism and potentially increase the risk of cardiovascular disease and metabolic disorders (Ko & Jung, 2021). People often also experience increased blood pressure, blood glucose, lipid levels, and inflammatory markers, increasing their risk for metabolic syndrome and cardiovascular disease (Hyvärinen et al., 2022). Therefore, these patients should be monitored for these chronic diseases.
Some of these metabolic shifts may mimic hypothyroidism or decreased thyroid function . This is one of the most common diseases in humans, particularly in older adults (Han et al., 2022), with many people dealing with both subclinical hypothyroidism and menopausal symptoms (Xu et al., 2023). Many of the clinical manifestations of hypothyroidism are similar to those experienced during menopause, including fatigue, weight gain, and anxiety. Like menopause, hypothyroidism is associated with negative changes in the lipid profile (Han et al., 2022) and requires ongoing monitoring.
Emotional Changes
Emotional well-being can be significantly impacted during perimenopause and menopause due to hormonal fluctuations and psychosocial factors. Mood swings, irritability, and episodes of depression may occur. Many people report feeling similar to the way they feel during premenstrual syndrome: moody, low energy, tearful, easily distracted, or irritable (Silver, 2023). However, unlike PMS, these symptoms have no relationship to the menstrual cycle and may occur for a long period of time without any discernible pattern (Silver, 2023). In addition to mood swings, many people report depression and anxiety, even if they have never had them before. Potential causes may include:
- hormonal changes
- dealing with physical symptoms associated with menopause
- increased life pressures and stress (Silver, 2023)
These emotional changes can affect a person’s quality of life and interpersonal relationships, highlighting the importance of emotional support and holistic care from the entire health-care team and especially the nurse.
Management
Diagnostic testing involves assessing hormone levels, especially follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol. During perimenopause and menopause, the ovaries are less responsive to these hormones, requiring increased levels to activate follicular growth (Eunice Kennedy Shriver National Institute of Child Health and Human Development, 2021). Elevated FSH levels and decreased estradiol levels are indicative of perimenopause and menopause. However, it is important to recognize that these hormones do vary throughout the cycle, and a single elevated FSH level is not enough to definitively tell that someone is in perimenopause (Endocrine Society, n.d.). An additional test is the anti-Müllerian hormone (AMH) level. Anti-Müllerian hormone is produced by the ovarian follicles. When there are a lot of follicles (high ovarian function), the AMH level is high; when ovarian function starts to decline, the AMH level drops as well (Endocrine Society, n.d.). If a patient presents with symptoms of perimenopause, the provider may order additional testing to determine if the symptoms could be attributed to a different cause, such as thyroid dysfunction, pituitary tumor , or even possible pregnancy.
The primary medical intervention for perimenopause and menopause includes hormone replacement therapy ( HRT ). HRT is the administration of estrogen, progesterone, or a combination of both hormones to effectively alleviate menopausal symptoms, such as vasomotor symptoms and vaginal dryness. In the past, the use of HRT was controversial due to a study that suggested significant health risks associated with its use; however, ongoing research has shown that HRT is a safe option for most healthy, menopausal people. Some populations of people should not use hormonal therapy , including people with a history of
- breast cancer,
- uterine cancer,
- deep vein thrombosis or pulmonary embolism,
- blood clotting disorder,
- migraine with aura ,
- liver disease , and
- arterial thrombotic disease (heart attack or stroke) (Harper-Harrison & Shanahan, 2023).
Patients who are not eligible for HRT have had success in reducing vasomotor symptoms using serotonin receptor reuptake inhibitors.
There are two types of HRT: estrogen only and combination estrogen/progesterone therapy. People with an intact uterus must take both estrogen and progesterone because estrogen alone can cause endometrial hyperplasia and increase the risk for uterine cancer (Harper-Harrison & Shanahan, 2023). Progesterone opposes estrogen and reduces that risk by keeping the uterine lining from uncontrolled proliferation (Harper-Harrison & Shanahan, 2023). In addition, progesterone may relieve other symptoms not affected by estrogen, such as insomnia and mood swings (Harper-Harrison & Shanahan, 2023). Estrogen and progesterone can be administered via patches, creams, pills, vaginal inserts, or subdermal pellets, depending on patient preference and clinical status. It is important for the patient to be aware of the risks of HRT, including deep vein thrombosis , strokes, and pulmonary embolism , similar to the risk of birth control pills.
Nonpharmacologic approaches can be used in lieu of or to complement medical treatments. Some lifestyle modification s may contribute to overall well-being and wellness, including:
- maintaining a balanced diet rich in calcium and vitamin D
- engaging in regular physical activity
- practicing stress reduction techniques
- quitting smoking
- reducing alcohol consumption
- managing weight (Endocrine Society, 2022a).
Cognitive behavioral therapy (CBT) and mindfulness practices aid in managing mood swings and emotional changes.
Nurses play a pivotal role in supporting people through perimenopause and menopause. Providing patient education about the physical and emotional changes, available treatment options, and self-care strategies empowers patients to actively participate in their health-care decisions. Creating a safe space for open discussions, offering emotional support, and assisting in symptom management are central to nursing care during this transitional phase.
Nonpharmacologic Measures for Menopause
The use of hormone replacement therapy (HRT) for menopausal symptoms is a personal decision. Many people are either uncomfortable with or unable to take these drugs and must treat their menopausal symptoms using nonpharmacologic options. The nurse plays an instrumental role in helping the patient find options that work for them. These may include:
- using a fan or wearing lightweight pajamas
- wearing layers
- stress reduction
- acupuncture
- yoga to reduce hot flashes
- mind-body therapies
- biofeedback
- meditation
- cognitive behavioral therapy (Johnson et al., 2019)
In addition to discussing these different options, the nurse may help the patient find a qualified practitioner to administer these treatments.
Endometriosis
The chronic and often painfully debilitating gynecologic disorder characterized by the presence of endometrial-like tissue outside the uterus is called endometriosis (World Health Organization, 2023). This tissue (Figure 6.2) can develop on various pelvic structures, such as the ovaries, bladder, rectovaginal septum , fallopian tubes, and the peritoneal lining (World Health Organization, 2023). Rarely, endometrial implants have been found outside the pelvis on other structures. It is believed that at least 11 percent of persons assigned female at birth in the United States have endometriosis (HHS Office on Women’s Health, 2021a). It is most common in a person’s 30s or 40s, but endometriosis can occur in anyone having menstrual periods (HHS Office on Women’s Health, 2021a). Researchers are unsure about the cause of endometriosis but suspect that it may be related to problems with retrograde menstrual flow, hormonal or immune system abnormalities, genetic factors, or previous surgery on the uterus or abdominal area (HHS Office on Women’s Health, 2021a).
The hallmark symptoms of endometriosis include pelvic pain, dysmenorrhea, dyspareunia, and infertility. Patients may experience pain that varies in intensity and duration, often worsening during menstruation. If implants are found on the bowel or bladder, patients can have urinary or gastrointestinal symptoms as well, such as diarrhea, bloating, constipation, painful bowel movements during menstruation, or pain while passing urine (World Health Organization, 2023). Sometimes, people have pain during or after sex or spotting between menstrual periods (HHS Office on Women’s Health, 2021a). Additionally, some patients may have asymptomatic endometriosis, highlighting the variability in symptom expression.
Diagnosing endometriosis starts with taking a detailed patient history, including information about symptoms, such as menstrual changes and pelvic pain. The provider should perform a physical assessment, including a pelvic exam, to evaluate for endometrial cysts or scars on the pelvic organs (HHS Office on Women’s Health, 2021a). Diagnostic testing, such as pelvic ultrasound and magnetic resonance imaging ( MRI ), can be used to visualize the pelvic anatomy. Laparoscopic surgery for direct visualization of endometrial implants and histologic confirmation remains the gold standard for definitive diagnosis. However, laparoscopic surgery is highly invasive and not necessary for providers to initiate treatment options to relieve pain and improve quality of life (World Health Organization, 2023).
The management of endometriosis focuses on alleviating pain, improving quality of life, and addressing fertility concerns. Pharmacologic options include:
- NSAID s for pain relief
- hormonal therapies such as oral contraceptives, progestins, and gonadotropin-releasing hormone (GnRH) agonists to suppress endometrial growth
In cases of severe pain or refractory symptoms, laparoscopic excision surgery can be considered to remove endometriotic lesions and improve fertility prospects (HHS Office on Women’s Health, 2021a). In many cases, the discomfort associated with endometriosis goes away during menopause, when estrogen levels decline and the endometrial lining shrinks (HHS Office on Women’s Health, 2021a). See Chapter 4 Influences on Fertility for additional information about managing endometriosis-related infertility.
Nonpharmacologic measures play a complementary role in managing endometriosis. Lifestyle modification s, including a balanced diet and regular exercise, can help manage inflammation and improve overall well-being. Some people find success from other therapies, such as:
- chiropractic care
- acupuncture
- certain herbal medications (cinnamon twig, licorice root)
- vitamin supplements (vitamin B1, magnesium , omega-3 fatty acids ) (HHS Office on Women’s Health, 2021a)
Nurses play a pivotal role in caring for persons with endometriosis. Patient education is very important when caring for patients with this condition to ensure that they understand their condition, treatment options, and potential outcomes. Nurses can provide information on medication management, potential side effects, and self-care strategies.
Patient-centered care involves active listening and acknowledging the physical and emotional impact of endometriosis. Nurses can offer coping strategies, facilitate support groups, and connect patients with relevant resources. When surgery is part of the treatment plan, nurses provide preoperative education, offer emotional support, and guide patients through postoperative recovery.
Polycystic Ovary Syndrome (PCOS)
Polycystic ovary syndrome ( PCOS ) is a common endocrine disorder found in approximately 6 percent to 12 percent of American persons assigned female at birth who are of childbearing age (Centers for Disease Control and Prevention [CDC], 2022b). PCOS is characterized by hormonal imbalances that lead to a variety of reproductive, metabolic, and cardiovascular disturbances (Figure 6.3) that present as a combination of multiple symptoms, affecting various aspects of a person’s health beyond their reproductive years (CDC, 2022b). Patients of every race and ethnicity suffer from PCOS. The cause of PCOS is not fully understood, but researchers have observed a pattern of elevated androgen levels and insulin resistance in people with the condition (CDC, 2022b). Researchers are also investigating how genetics may contribute to developing this disease, as many people with PCOS have relatives with this disorder (CDC, 2022b).
The symptoms of PCOS are diverse and vary significantly from person to person. Many people do not realize they have the condition until they struggle to conceive. Other people have the full spectrum of clinical manifestations, which can include:
- irregular menstrual cycles
- hyperandrogenism , causing hirsutism (excessive hair growth), acne, and alopecia
- polycystic ovaries seen on ultrasound
- obesity
People with PCOS are also at higher risk for several serious complications, including:
- insulin resistance and diabetes
- metabolic syndrome
- hypertension
- high cholesterol and triglycerides
- endometrial cancer due to excessive endometrial growth from irregular menstrual cycles
- depression and anxiety
- obstructive sleep apnea related to being overweight
- cardiovascular disease
- non-alcoholic fatty liver disease
- infertility (Endocrine Society, 2022b)
People with PCOS who become pregnant are at higher risk for complications such as gestational diabetes , preeclampsia , and preterm birth (Endocrine Society, 2022b).
Diagnosing PCOS involves a thorough assessment of a patient’s medical history and clinical symptoms, as well as diagnostic testing when necessary. The diagnostic tool for PCOS is the Rotterdam criteria, which require the presence of two out of three factors: menstrual irregularity, evidence of hyperandrogenism (by either clinical symptoms or laboratory testing), and polycystic ovaries visualized on ultrasound (Christ & Cedars, 2023). To be diagnostic of PCOS, these symptoms must also occur without any other clinical cause. Blood tests can be used to rule out other diagnoses, including pregnancy, elevated prolactin levels, and abnormal levels of thyroid hormones and follicle-stimulating hormone. Testing of androgen levels, such as testosterone and dehydroepiandrosterone sulfate (DHEAS), may also aid in the diagnosis (Barbieri & Ehrmann, 2023). After diagnosis of PCOS, patients may undergo testing for insulin resistance, diabetes , and cholesterol/triglyceride levels to determine if other complications are present (Barbieri & Ehrmann, 2023).
The management of PCOS is multifaceted, focusing on alleviating symptoms, improving metabolic outcomes, and addressing reproductive concerns. Combined oral contraceptive s (COCs), in the form of pills, patches, or the vaginal ring, are frequently used to help regulate menstrual cycles, lower the risk of endometrial hyperplasia, and reduce hyperandrogenism (Barbieri & Ehrmann, 2023). COCs can be used in combination with antiandrogens, such as spironolactone (Aldactone), to help further reduce symptoms of hyperandrogenism, like hirsutism and acne. Hair removal therapies, such as depilatories, laser therapy, waxing or shaving, and electrolysis, are also effective in removing excess hair. Hair loss, on the other hand, can be treated with medications or hair replacement therapies. Weight loss is a common concern for people with PCOS and should be approached with reducing insulin resistance in mind. While diet and exercise are key, weight loss medication or surgery may also be necessary due to the complicated metabolic disturbances that may be present. Metformin (Glucophage), an insulin-sensitizing medication, can be effective in improving insulin resistance and may help to restore ovulation in people with abnormal menstrual cycles. See Chapter 4 Influences on Fertility for additional information about addressing fertility concerns for people with PCOS.
Lifestyle modifications are essential in managing PCOS, particularly for improving metabolic health and fertility outcomes. Regular physical activity and a balanced diet can help manage weight, reduce insulin resistance, and promote overall well-being. Weight loss, even modest, can lead to improvements in menstrual regularity, hormonal profiles, and fertility (Barbieri & Ehrmann, 2023). Nurses play a vital role in supporting patients with PCOS through education, counseling, and emotional support. Patient education is crucial in helping persons understand their condition, treatment options, and potential long-term health implications. Nurses can offer guidance on lifestyle modification s, emphasizing the importance of regular exercise, balanced nutrition, and weight management.
For people experiencing infertility due to PCOS, nurses can provide emotional support during fertility treatments and assist in coordinating care with fertility specialists. Educating patients about potential fertility interventions, such as ovulation induction and in vitro fertilization (IVF) , enables informed decision making. Chapter 4 Influences on Fertility provides additional information about nursing care for the patient undergoing diagnostic testing or treatment for infertility. Furthermore, nurses collaborate with multidisciplinary health-care teams, including endocrinologists, dieticians, and mental health professionals, to ensure comprehensive care.
Metformin
Metformin is a medication commonly prescribed for people with PCOS to help improve insulin sensitivity. It can also help restore ovulation in PCOS with insulin resistance and is sometimes used in the infertility setting for that purpose.
- Generic Name: metformin
- Trade Name: Fortamet, Glucophage, Glumetza
- Class/Action: biguanide drug
- Route/Dosage: Oral medication prescribed at daily doses between 500 and 2,550 mg. Immediate-release formulations are administered twice daily, preferably with a meal, and extended-release formulas are taken once a day with the evening meal. Dosages typically start at 500 mg once or twice each day and are titrated each week in increments of 500 mg (Corcoran & Jacobs, 2023).
- High Alert/Black Box Warning: Lactic acidosis is a rare complication that can occur in some people with metformin use. It is characterized by elevated lactate levels, decreased pH, and other electrolyte abnormalities. This complication occurs rarely, at approximately 0.03 cases per 1,000 patient-years (Crowley et al., 2016).
- Indications: Indicated for the treatment of type 2 diabetes. It is used off-label to manage gestational diabetes, weight gain from antipsychotic medication, and polycystic ovary syndrome (Corcoran & Jacobs, 2023).
- Mechanism of Action: Biguanides lower blood glucose levels by three mechanisms: (1) improving insulin sensitivity, (2) reducing absorption of glucose in the gut, and (3) lowering glucose production in the liver (Corcoran & Jacobs, 2023). In people with PCOS, metformin reduces insulin levels, which normalizes luteinizing hormone (LH) and androgens, which helps in restoring regular ovulation (Corcoran & Jacobs, 2023).
- Contraindications: Metformin is contraindicated in patients with renal disease, people with hypersensitivity to metformin, or people with metabolic acidosis.
- Adverse Reactions/Side Effects: The most common adverse effects with metformin use are gastrointestinal effects, including diarrhea, nausea, and vomiting. This is mitigated by having patients take the medication with food and titrating doses slowly. Other side effects may include headache, hypoglycemia, weakness, and rhinitis.
- Nursing Implications: It is important for the nurse to educate the patient about this drug, especially about the signs and symptoms of lactic acidosis, and the expected side effects. The nurse should also warn the patient about the potential GI side effects and offer advice on how to reduce these. The nurse should also review lifestyle modifications that can be helpful in people with PCOS and insulin resistance.
Chronic Pelvic Pain
Chronic pelvic pain (CPP) is a condition characterized by persistent or recurrent pain in the pelvic region lasting for at least 6 months. This type of pain can come and go over that 6-month period or occur at regular intervals, such as during particular events of the menstrual cycle or with certain activities, such as during sex (ACOG, 2022c). The diversity of symptoms highlights the complexity of CPP and its potential underlying causes. CPP can be related to disorders of the reproductive organs, bladder or urinary tract, or the bowel and can be caused by conditions such as:
- endometriosis
- fibroids
- irritable bowel syndrome
- interstitial cystitis
- urinary tract infection
- dysmenorrhea
- pelvic inflammatory disease (PID)
- cancer of the urinary or gastrointestinal tract
- poor posture
- strain of the structures in the low back related to pregnancy
- musculoskeletal problems or low back pain and disc injuries (ACOG, 2022c)
CPP can significantly impact a person’s physical, emotional, and social well-being. In many cases, up to 50 percent, the cause of CPP is never diagnosed (Dydyk & Gupta, 2023).
Diagnosing CPP requires a comprehensive evaluation involving medical history, physical examination, and targeted diagnostic tests. The provider will explore the patient’s symptoms and their relationship with precipitating and alleviating factors, such as menses, urination, sexual activity, and bowel movements (Dydyk & Gupta, 2023). If connections are found, they should be explored further. For example, if the patient experiences pain related to urination, diagnostic testing for urinary tract infection, interstitial cystitis, and other urinary abnormalities should be the next step. Most importantly, the provider should also ask about symptoms that may signal systemic disease, such as unexplained weight loss, bleeding in the urine or stool, bleeding after sex, or bleeding between periods or after menopause. The physical exam should include assessment of the abdomen and reproductive structures, including a gynecologic exam (Dydyk & Gupta, 2023). Pelvic ultrasound , computed tomography (CT) scans, and magnetic resonance imaging ( MRI ) can help identify structural abnormalities, such as ovarian cyst s, fibroid s, or endometriosis. Diagnostic laparoscopy , a minimally invasive surgical procedure, can provide direct visualization and potential treatment of underlying conditions.
The management of CPP focuses on addressing the underlying cause:
- antibiotics for pelvic inflammatory disease or urinary tract infection
- hormonal contraceptives for dysmenorrhea or endometriosis
- surgical removal of cysts and fibroids
- physical therapy for musculoskeletal issues
- medication for irritable bowel disease or interstitial cystitis
If no specific cause for the pain is found, treatment shifts to managing the pain and improving quality of life. This may include the use of NSAID s for pain relief or gabapentin (Neurontin) or pregabalin (Lyrica) for neuropathic pain (ACOG, 2022c). In some cases, surgical interventions may be considered to address structural issues contributing to CPP.
Nonpharmacologic measures play a pivotal role in managing CPP and can be used to complement other medical treatments. Strategies such as physical therapy, pelvic floor exercises, and relaxation technique s can help improve muscular function, alleviate pain, and reduce stress. Regular exercise and weight loss can improve posture and some musculoskeletal issues contributing to CPP (ACOG, 2022c). Nutritional interventions and dietary modifications can contribute to managing bowel and urinary symptoms associated with CPP. Other pain management strategies, such as acupuncture , acupressure, nerve stimulation, biofeedback therapy, and even nerve blocks can also be helpful in some cases (ACOG, 2022c).
Nurses play a vital role in providing comprehensive care and support to persons with CPP. Assessment is key, involving a thorough evaluation of the patient’s pain history, symptoms, and psychosocial factors contributing to pain perception. Fifty-three percent of patients with CPP experience moderate to severe depression and anxiety (Bryant et al., 2016). Empathetic listening and effective communication are essential to understanding the impact of CPP on the patient’s daily life. Patient education is a cornerstone of nursing interventions. Nurses can educate patients about their condition, potential treatment options, and strategies for managing pain and associated symptoms. Teaching relaxation techniques, guiding patients through pelvic exercises, and providing information about available resources empower persons to actively participate in their care. Furthermore, nurses collaborate with interdisciplinary teams, including physicians, physical therapists, psychologists, and pain specialists, to develop comprehensive treatment plans tailored to the patient’s needs. Emotional support, counseling, and facilitating support groups can help address the psychologic impact of CPP.


Questions to consider:
-
Is time management different in college from what I am used to?
-
How different is college schoolwork from high school work?
You may find that time management in college is very different from anything you have experienced previously. For the last 12 years, almost all your school time was managed by educators and your parents. What you did and when you did it was controlled by others. In many cases, even after-school time was set by scheduled activities (such as athletics) and by nightly homework that was due the next day.
In the workplace, the situation is not very different, with activities and time on task being monitored by the company and its management. This is so much a part of the working environment that many companies research how much time each task should take, and they hold employees accountable for the time spent on these job functions. In fact, having these skills will help you stand out on the job and in job interviews.
Differences between K12 and College
|
K–12
|
College
|
|
Many class activities are planned.
|
Class time is given to receiving information.
|
|
Homework is often similar for each student.
|
You may have freedom in homework choices.
|
|
Time is managed by others more often.
|
Time is managed by the student.
|
Table 4.2 Differences between K-12 to College
In college, there is a significant difference because a great deal of time management is left up to you. While it is true that there are assignment due dates and organized classroom activities, learning at the college level requires more than just the simple completion of work. It involves decision-making and the ability to evaluate information. This is best accomplished when you are an active partner in your own learning activities.
Figure 4.2: Students may set aside specific times and specific places to study.
As an example of how this works, think about a college assignment that involves giving a classroom presentation. To complete the assignment, you are given time to research and reflect on the information found. As a part of the assignment, you must reach your own conclusions and determine which information that you have found is best suited for the presentation. While the date of the actual presentation and how long it will last are usually determined by the instructor, how much time you spend gathering information, the sources you use, and how you use them are left to you.
WHAT STUDENTS SAY
-
How difficult is it for you to keep track of multiple tasks over the course of a term?
-
Extremely easy
-
Somewhat easy
-
Somewhat difficult
-
Extremely difficult
-
Do you use a particular app to help you manage your time?
-
I use Google calendar
-
I use the calendar on my phone
-
I use a paper/notebook planner
-
I use the calendar on my learning management system
-
I use another app or system
-
I don't use any type of planner or app
-
Rank the following in terms of what you would most like to improve regarding your time management skills.
-
My ability to predict how much time my tasks will take.
-
My ability to balance various obligations.
-
My ability to avoid procrastination.
-
My ability to limit distractions.
You can also take the anonymous
What Students Say(opens in new window)
surveys to add your voice to this textbook. Your responses will be included in updates.
Students offered their views on these questions, and the results are displayed in the graphs below.
How difficult is it for you to keep track of multiple tasks over the course of a term?
Figure 4.3
Do you use a particular app to help you manage your time?
Figure 4.4
Rank the following in terms of what you would most like to improve regarding your time management skills.
Figure 4.5
You Have Lots of Time to Manage
For college-level learning, this approach is important enough that you can expect to spend much more time on learning activities outside the classroom than you will in the classroom. In fact, the estimated time you should spend will be at least two hours of outside learning for every one hour of lecture. Some weeks may be more intense, depending on the time of the semester and the courses you are taking. If those hours are multiplied over several courses in a given session, you can see how there is a significant amount of time to manage. Unfortunately, many students do not always take this into consideration, and they spend far less time than is needed to be successful. The results of poor time management are often a shock to them.
“In college, as an active participant in your own education, what you do and when you do it is largely determined by you.”
The Nature of What You Have to Do Has Changed
Returning to our example of the classroom-presentation assignment, you can see that the types of learning activities in college can be very different from what you have experienced previously. While there may have been similar assignments in high school, such as presentations or written papers, the level of expectation with length and depth is significantly different in college. This point is made very clear when comparing facts about the requirements of high school work to the type of work students produce in college. One very strong statistic that underscores this comes from a study conducted by the Pew Research Center. They found that 82 percent of teens report that their typical high school writing assignments were only a single paragraph to one page in length.
2
(Writing Technology and Teens, 2004, Pew Research Center) This is in stark contrast to a number of sources that say that writing assignments in lower-level college courses are usually 5–7 pages in length, while writing assignments in upper-level courses increase to 15–20 pages.
It is also interesting to note that the amount of writing done by a college student can differ depending on their program of study. The table below indicates the estimated average amount of writing assigned in several disciplines. To estimate the number of pages of assigned writing, the average number of writing assignments of a given page length was multiplied by an approximate number of pages for the assignment type (see
Estimating Number of Pages Written
for calculation details).
Table 4.3 Credit: Updated NSSE (Since 2013)
|
Writing Assignments Vary in Length
|
|
Discipline
|
Number of Pages Assigned in Introductory Course
|
|
Arts & Humanities
|
49
|
|
Biological Sciences, Agriculture, & Natural Resources
|
47
|
|
Physical Sciences, Mathematics, & Computer Science
|
44
|
|
Social Sciences
|
52
|
|
Business
|
48
|
|
Communications, Media, & Public Relations
|
50
|
|
Education
|
46
|
|
Engineering
|
46
|
|
Health Professions
|
43
|
|
Social Service Professions
|
47
|
High school homework often consists of worksheets or tasks based on reading or classroom activities. In other words, all the students are doing the same tasks, at relatively the same time, with little autonomy over their own education.
Using the earlier example of the presentation assignment, not only will what you do be larger in scale, but the depth of understanding and knowledge you will put into it will be significantly more than you may have encountered in previous assignments. This is because there are greater expectations required of college graduates in the workplace. Nearly any profession that requires a college degree has with it a level of responsibility that demands higher-level thinking and therefore higher learning. An often-cited example of this is the healthcare professional. The learning requirements for that profession are strict because we depend on those graduates for our health and, in some cases, our lives. While not every profession may require the same level of study needed for healthcare, most do require that colleges maintain a certain level of academic rigor to produce graduates who are competent in their fields.


22.3: Star Clusters
By the end of this section, you will be able to:
- Explain how star clusters help us understand the stages of stellar evolution
- List the different types of star cluster s and describe how they differ in number of stars, structure, and age
- Explain why the chemical composition of globular clusters is different from that of open clusters
The preceding description of stellar evolution is based on calculations. However, no star completes its main-sequence lifetime or its evolution to a red giant quickly enough for us to observe these structural changes as they happen. Fortunately, nature has provided us with an indirect way to test our calculations.
Instead of observing the evolution of a single star, we can look at a group or cluster of stars. We look for a group of stars that is very close together in space, held together by gravity, often moving around a common center. Then it is reasonable to assume that the individual stars in the group all formed at nearly the same time, from the same cloud, and with the same composition. We expect that these stars will differ only in mass. And their masses determine how quickly they go through each stage of their lives.
Since stars with higher masses evolve more quickly, we can find clusters in which massive stars have already completed their main-sequence phase of evolution and become red giants, while stars of lower mass in the same cluster are still on the main sequence, or even—if the cluster is very young—undergoing pre-main-sequence gravitational contraction. We can see many stages of stellar evolution among the members of a single cluster, and we can see whether our models can explain why the H–R diagrams of clusters of different ages look the way they do.
The three basic types of clusters astronomers have discovered are globular cluster s, open cluster s, and stellar association s. Their properties are summarized in Table 22.3. As we will see in the next section of this chapter, globular clusters contain only very old stars, whereas open clusters and associations contain young stars.
| Characteristic | Globular Clusters | Open Clusters | Associations |
|---|---|---|---|
| Number in the Galaxy | 150 | Thousands | Thousands |
| Location in the Galaxy | Halo and central bulge | Disk (and spiral arms) | Spiral arms |
| Diameter (in light-years) | 50–450 | <30 | 100–500 |
| Mass M Sun | 10 4 –10 6 | 10 2 –10 3 | 10 2 –10 3 |
| Number of stars | 10 4 –10 6 | 50–1000 | 10 2 –10 4 |
| Color of brightest stars | Red | Red or blue | Blue |
| Luminosity of cluster ( L Sun ) | 10 4 –10 6 | 10 2 –10 6 | 10 4 –10 7 |
| Typical ages | Billions of years | A few hundred million years to, in the case of unusually large clusters, more than a billion years | Up to about 10 7 years |
Globular Clusters
Globular clusters were given this name because they are nearly symmetrical round systems of, typically, hundreds of thousands of stars. The most massive globular cluster in our own Galaxy is Omega Centauri , which is about 16,000 light-years away and contains several million stars (Figure 22.6). Note that the brightest stars in this cluster, which are red giants that have already completed the main-sequence phase of their evolution, are red-orange in color. These stars have typical surface temperatures around 4000 K. As we will see, globular clusters are among the oldest parts of our Milky Way Galaxy.
What would it be like to live inside a globular cluster? In the dense central regions, the stars would be roughly a million times closer together than in our own neighborhood. If Earth orbited one of the inner stars in a globular cluster, the nearest stars would be light-months, not light-years, away. They would still appear as points of light, but would be brighter than any of the stars we see in our own sky. The Milky Way would probably be difficult to see through the bright haze of starlight produced by the cluster.
About 150 globular clusters are known in our Galaxy. Most of them are in a spherical halo (or cloud) surrounding the flat disk formed by the majority of our Galaxy’s stars. All the globular clusters are very far from the Sun, and some are found at distances of 60,000 light-years or more from the main disk of the Milky Way. The diameters of globular star clusters range from 50 light-years to more than 450 light-years.
Open Clusters
Open clusters are found in the disk of the Galaxy. They have a range of ages, some as old as, or even older than, our Sun. The youngest open clusters are still associated with the interstellar matter from which they formed. Open clusters are smaller than globular clusters, usually having diameters of less than 30 light-years, and they typically contain only several dozen to several hundreds of stars (Figure 22.7). The stars in open clusters usually appear well separated from one another, even in the central regions, which explains why they are called “open.” Our Galaxy contains thousands of open clusters, but we can see only a small fraction of them. Interstellar dust, which is also concentrated in the disk, dims the light of more distant clusters so much that they are undetectable.
Although the individual stars in an open cluster can survive for billions of years, they typically remain together as a cluster for only a few million years, or at most, a few hundred million years. There are several reasons for this. In small open clusters, the average speed of the member stars within the cluster may be higher than the cluster’s escape velocity, 1 and the stars will gradually “evaporate” from the cluster. Close encounters of member stars may also increase the velocity of one of the members beyond the escape velocity. Every few hundred million years or so, the cluster may have a close encounter with a giant molecular cloud, and the gravitational force exerted by the cloud may tear the cluster apart.
Several open clusters are visible to the unaided eye. Most famous among them is the Pleiades (Figure 20.13), which appears as a tiny group of six stars (some people can see even more than six, and the Pleiades is sometimes called the Seven Sisters). This cluster is arranged like a small dipping spoon and is seen in the constellation of Taurus, the bull. A good pair of binoculars shows dozens of stars in the cluster, and a telescope reveals hundreds. (A car company, Subaru, takes its name from the Japanese term for this cluster; you can see the star group on the Subaru logo.)
The Hyades is another famous open cluster in the constellation of Taurus the bull. To the naked eye, it appears as a V-shaped group of faint stars marking the face of the bull. Telescopes show that Hyades actually contains more than 200 stars.
Stellar Associations
An association is a group of extremely young stars, typically containing 5 to 50 hot, bright O and B stars scattered over a region of space some 100–500 light-years in diameter. As an example, most of the stars in the constellation Orion form one of the nearest stellar association s. Associations also contain hundreds to thousands of low-mass stars, but these are much fainter and less conspicuous. The presence of really hot, luminous stars indicates that star formation in the association has occurred in the last million years or so. Since O stars go through their entire lives in only about a million years, they would not still be around unless star formation has occurred recently. It is therefore not surprising that associations are found in regions rich in the gas and dust required to form new stars. It’s like a brand new building still surrounded by some of the construction materials used to build it and with the landscape still showing signs of construction. On the other hand, because associations, like ordinary open clusters, lie in regions occupied by dusty interstellar matter, many are hidden from our view.
Footnotes
- 1 Escape velocity is the speed needed to overcome the gravity of some object or group of objects. The rockets we send up from Earth, for example, must travel faster than the escape velocity of our planet to be able to get to other worlds.


26.5: Test #5
Note: This test may need to be updated and/or revised to accurately reflect current statistics, research findings, and health trends.
1. What is a potential benefit of replacing “unhealthy fats” with “healthy fats” in your diet?
a. It may increase your LDL cholesterol levels.
b. It may reduce your LDL cholesterol levels.
c. It may increase your blood glucose levels.
d. It has no effect on your cholesterol levels.
2.  Olive oil is a good choice to consider when trying to incorporate more “healthy fats” into your diet.
a. True
b. False
4. Which type of fiber has been shown to potentially help lower “bad” cholesterol levels?
a. insoluble
b. high density
c. low density
d. soluble
5. Which nutrient would be the most helpful in promoting regularity (i.e. relieving constipation)?
a. protein
b. calcium
c. soluble fiber
d. insoluble fiber
6. Explain what type 2 diabetes is (i.e. what happens in the body), and discuss how/why it can damage the body over time:
7. Anxiety disorders affect approximately how many American adults in a given year?
a. 10 million
b. 20 million
c. 40 million
d. 80 million
8. List five symptoms of depression:
a.
b.
c.
d.
e.
9. Identify and briefly explain each stage of Maslow’s Hierarchy of Needs in the correct order below:
10. Choose ONE of the following defense mechanisms, and explain what it is:
- Repression
- Denial
- Rationalization
- Projection
- Displacement
- Regression
- Sublimation
11. Which eating disorder best describes behaviors that involve periods of overeating, followed by purging?
a. anorexia nervosa
b. bulimia nervosa
c. binge-eating
d. all of the above
12. Generalized Anxiety Disorder (GAD) is diagnosed when a person worries excessively about a variety of everyday problems for…?
a. at least 2 weeks
b. at least 1 month
c. at least 6 months
d. at least 1 year
13. Agoraphobia can best be described as a fear of…?
a. public places
b. farms
c. horror films
d. math
14. A treatment approach in which a person gradually encounters the object or situation that is feared, perhaps at first only through pictures or videos, then later face-to-face, is known as…?
a. aversion therapy
b. psychoanalysis
c. existential therapy
d. exposure-based therapy
15. Major depression is an episode of sadness or apathy along with other symptoms that lasts at least ______________ and is severe enough to interrupt daily activities.
a. 2 consecutive weeks
b. 2 consecutive months
c. 6 consecutive weeks
d. 6 consecutive months
16. Long-term milder symptoms, lasting 2 years or longer, that prevent normal functioning or feeling well, is best described as which condition?
a. major depression
b. panic disorder
c. dysthymia
d. bipolar disorder
17. The FDA has placed a “black box” warning label on all antidepressant medications to alert the public about the potential increased risk of…?
a. dangerous interactions that may occur with over-the-counter (OTC) products
b. elevating blood pressure levels
c. suicidal thinking or attempts in children, adolescents, and young adults
d. suffering from a heart attack
18. Place a check mark beside EACH fat-soluble vitamin below:
_____ Vitamin C
_____ Vitamin D
_____ Thiamin
_____ Vitamin A
_____ Vitamin E
_____ Vitamin B-12
19. What is found in certain foods that can help protect the body from damage by free radicals?
a. psyllium
b. amino acids
c. antioxidants
d. none of the above
20. The words “organic” and “natural” mean the same thing on food labeling, and must adhere to the same standards.
a. True
b. False
- Test #5. Authored by : Trina DiGregorio, M.S.. Provided by : Monroe Community College. License : CC BY: Attribution


7.6: Applied Examples
To better understand the concepts learned in this chapter, apply them to real-life situation and every day problems.
The total sales of phone covers in a popular phone store (in thousands) are shown in the figure below. The month of March, \(2016\), corresponds to \(x = 0\).
- Refer to the figure above to write an equation of the line that models the data. What does the slope indicate?
- Use the equation in part a to approximate the sales of phone covers in the month of November, \(2016\).
Solution
- Referring to the figure above, notice that there are two points, \((0, 2890)\) and \((4, 5500)\), that lie on the given line. Use the two points to first find the slope. Thus,
\(m = \dfrac{5500 − 2890}{4 − 0} = \dfrac{2610}{4} = 652.5\)
Thus, the slope is \(652.5\). Since the slope is positive, it indicates an increase. Hence, the slope indicates that the sales of phone covers have increased by about \($652.5\) per month from March \(2016\) to July \(2016\).
Use the slope and the \(y\)-intercept \((0, 2890)\) to write the equation of the line in slope-intercept form as follows,
\(\begin{array} &&y = mx + b &\text{Slope-intercept form} \\ &y = 652.5x + 2890 &\text{Substituting \(m = 652.5\) and \(b = 2890\)} \end{array}\)
- Now, it is given that \(x = 0\) corresponds to the month of March and the problem asks to approximate the sales of phone covers in the month of November \(2016\). Thus, \(x = 8\) corresponds to the month of November \(2016\). Substitute \(x = 8\) in the equation found in part a. Thus,
\(\begin{array} &&y = 652.5x + 22980 &\text{Equation of the line from part a} \\ &= 652.5(8) + 2890 &\text{Substitute \(x = 8\)} \\ &= 8110 &\text{Multiply then add to simplify} \end{array}\)
Therefore, the sales of phone covers in the month of November \(2016\) were approximately \($8,110\).
 The toddler’s main calcium intake was in the form of milk. The mother recorded the data for nine months to monitor the toddler’s intake of milk. The data is represented in a scattered diagram that shows the amount of milk that the toddler consumed each month for nine months, from February to October as shown in the figure below.
- Refer to the figure above to write an equation of the line to model the given data using the two labeled points. Write the equation in a slope-intercept form. What can be said about the slope?
- Use the equation of the line found in part a to predict the amount of mild that the toddler will consume in December.
Solution
- To write the equation of the line, first find the slope using the two labeled points, \((3, 4.5)\) and \((8, 3.25)\). Thus,
\(m = \dfrac{3.25 − 4.5}{8 − 3} = −\dfrac{1.25}{5} = −0.25\)
The slope is negative means that the toddler’s milk consumption is decreasing by about \(0.25\) gallons of milk each month.
Since the \(y\)-intercept is not given, it will not be possible to use the slope intercept form. Instead, use the slope and either of the two labeled points in the point-slope form to find the equation of the line. Thus,
\(\begin{array} &&y − y_1 = m(x − x_1) &\text{Point-Slope form} \\ &y − 4.5 = −0.25(x − 3) &\text{Substitute \(m = −0.25\) and point \((3, 4.5)\) with \(x_1 = 3\) and \(y_1 = 4.5\)} \\ &y−4.5 = −0.25x+0.75 &\text{Distribute \(-0.25\) to both terms on the right} \\ &y = −0.25x + 5.25 &\text{Add \(4.5\) to both sides of the equality to solve for \(y\) and get the equation in the Slope-Intercept form} \end{array}\)
Thus, \(y = −0.25x + 5.25\) is the equation of the line that represents the data given in the figure above and is in slope-intercept form.
- To predict how many gallons of milk will the toddler consume in December, first find \(x\) that corresponds to the month of December. It is given that \(x = 0\) corresponds to the month of February. Starting at the month of March with \(x = 1\), \(x = 10\) corresponds to the month of December. Substitute \(x = 10\) in the equation of the line found in part a and solve for \(y\) as follows,
\(\begin{array} &&y = −0.25x + 5.25 &\text{Equation of the line found in part a} \\ &= −0.25(10) + 5.25 &\text{Substitute \(x = 10\)} \\ &= −2.5 + 5.25 &\text{Multiply then add to simplify} \\ &= 2.75 & \end{array}\)
Therefore, the toddler will consume about \(2.75\) gallons of milk in December.
The annual sales of a certain model of printers in a famous electronics store are shown in the figure below, where the year \(2012\) corresponds to \(x = 0\).
- Refer to the figure above to write an equation of the line that models the data. What does the slope indicate?
- Use the equation of the line found in part a to approximate the sales of the printers in the year \(2016\).
John bought an ice cream cone that is \(11.2\) cm tall. It was really hot, the ice cream started to melt at a rate of \(2\) cm per minute. John got interested at how fast his ice cream was melting and wanted to know how much ice cream would be left after \(2.5\) minutes.
- Find an equation of the line that models the data in slope-intercept form.
- Determine how much ice cream is left after \(2.5\) minutes.


4.3: Graphs and Properties of Exponential Growth and Decay Functions/Use TI-84 calculator
In this section, you will:
- Examine properties of exponential functions
- Examine graphs of exponential functions
- How to graph and evaluate an exponential function using the TI-84 calculator.
An exponential function can be written in forms
\[f(x) = ab^x = a(1 + r)^x = ae^{kx} \nonumber \]
where
- \(\mathbf{a}\) is the initial value because \(f(0) = a\). In the growth and decay models that we examine in this finite math textbook, \(a > 0\).
- \(\mathbf{b}\) is often called the growth factor . We restrict \(b\) to be positive (\(b > 0\)) because even roots of negative numbers are undefined. We want the function to be defined for all values of \(x\), but \(b^x\) would be undefined for some values of \(x\) if \(b<0\).
- \(\mathbf{r}\) is called the growth or decay rate . In the formula for the functions, we use r in decimal form, but in the context of a problem we usually state r as a percent.
- \(\mathbf{k}\) is called the continuous growth rate or continuous decay rate.
Properties of Exponential Growth Functions
The function \(y=f(x) = ab^x\) represents growth if \(b > 1\) and \(a > 0\).
The growth rate \(r\) is positive when \(b>1\). Because \(b = 1+ r > 1\), then \(r = b−1 > 0\)
The function \(y=f(x) = ae^{kx}\) represents growth if \(k > 0\) and \(a > 0\).
The function is an increasing function; \(y\) increases as \(x\) increases.
- Domain: { all real numbers} ; all real numbers can be input to an exponential function
- Range: If \(a>0\), the range is {positive real numbers} The graph is always above the x axis.
- Horizontal Asymptote: when \(b > 1\), the horizontal asymptote is the negative x axis, as x becomes large negative. Using mathematical notation: as x → −∞, then y → 0.
- The vertical intercept is the point \((0,a)\) on the y-axis. There is no horizontal intercept because the function does not cross the x-axis.
Properties of Exponential Decay Functions
The function \(y=f(x) = ab^x\) function represents decay if \(0 < b < 1\) and \(a > 0\).
The growth rate \(r\) is negative when \(0 < b < 0\). Because \(b=1+r < 1\), then \(r=b-1<0\).
The function \(y=f(x) = ae^{kx}\) function represents decay if \(k < 0\) and \(a > 0\).
The function is a decreasing function; \(y\) decreases as \(x\) increases.
Domain: { all real numbers} ; all real numbers can be input to an exponential function
Range: If \(a>0\), the range is { positive real numbers } The graph is always above the x axis.
Horizontal Asymptote: when \(b < 1\), the horizontal asymptote is the positive x axis as x becomes large positive. Using mathematical notation: as x → ∞, then y → 0.
The vertical intercept is the point \((0,a)\) on the y-axis. There is no horizontal intercept because the function does not cross the x-axis.
The graphs for exponential growth and decay functions are displayed below for comparison.
How to find an exponential function from two points
Suppose the following points define an exponential function that describes the exponential growth or decline of customers coming to a restaurant if the initial point is (0, 1). Find the exponential function.
a) (4, 625)
b) (-3, 343)
Solution
a) The general exponential function is y = ab x .
- Substituting the point (0, 1), you get 1 = ab 0 .
- We know that b 0 = 1; therefore, the exponential function is y = b x .
- Next, substitute the point (4, 625) in the exponential function 625 = b 4 .
- Take the 4th root of each side (625) (1/4) = b
- b = 5
- The exponential equation is y = 5 x .
b) The general exponential function is y = abx.
- Substituting the point (0, 1), you get 1 = ab 0 .
- We know that b 0 = 1; therefore, the exponential function is y = b x .
- Next, substitute the point (-3, 343) in the exponential function 343 = b -3 .
- A negative exponent indicates the b should be in the denominator 343 = (1/b) 3 .
- Take the cubic root of both sides (343) (1/3) = (1/b).
- 7 = (1/b)
- Multiply both sides by b and solve for b. 7b = (1/b)(b) = 1. b = 1/7
- The exponential equation is y = (1/7) x .
An Exponential Function is a One-to-One Function
Observe that in the graph of an exponential function, each y value on the graph occurs only once. Therefore, every y value in the range corresponds to only one x value. So, for any particular value of y, you can use the graph to see which value of x is the input to produce that y value as output. This property is called “ one-to-one ”.
Because for each value of the output y, you can uniquely determine the value of the corresponding input x, thus every exponential function has an inverse function. The inverse function of an exponential function is a logarithmic function, which we will investigate in the next section.
\(x\) years after the year 2015, the population of the city of Fulton is given by the function \(y= f(x) = 35000(1.03^x)\). \(x\) years after the year 2015, the population of the city of Greenville is given by the function \(y = g(x) = 80000(0.95^x)\). Compare the graphs of these functions.
Solution
The graphs below were created using computer graphing software. You can also graph these functions using a graphing calculator.
| Population of Fulton | Population of Greenville |
|---|---|
| \[y=f(x)=35000\left(1.03^{x}\right) \nonumber \] | \[y=g(x)=80000\left(0.95^{x}\right) \nonumber \] |
|
Fulton's population is increasing. \(b = 1.03 > 1\) and \(r=0.03>0\) Exponential Growth |
Greenville’s population is decreasing. \(b = 0.95 < 1\) and \(r = −0.05 < 0\) Exponential Decay |
|
|
|
|
y-intercept: (0, 35000) The initial population in 2015 is 35000. |
y-intercept: (0,80000) The initial population in 2015 is 80000. |
| Horizontal Asymptote: The negative x axis is the horizontal asymptote. y → 0 as x → − ∞ | Horizontal Asymptote: The positive x axis is the horizontal asymptote. y → 0 as x → ∞ |
Domain : In general, the domain of both functions \(y= f(x) = 35000(1.03^x)\) and \(y= g(x) = 80000(0.95^x)\) is the set of all real numbers.
Range : The range of both functions is the set of positive real numbers. Both graphs always lie above the x-axis.
Domain and Range in context of this problem:
The functions represent population size as a function of time after the year 2015 . We restrict the domain in this context, using the “practical domain” as the set of all non-negative real numbers: \(x≥0\). Then we would consider only the portion of the graph that lies in the first quadrant.
- If we restrict the domain to \(x≥0\) for the growth function \(y= f(x) = 35000(1.03^x)\), then the range for the population of Fulton is \(y ≥ 35,000\)
- If we restrict the domain to \(x≥0\) for the decay function \(y= g(x) = 80000(0.95^x)\), then the range for the population of Greenville is \(y ≤ 80,000\).
How to graph an exponential function
Graph y = 2 x using the TI-84 calculator. Evaluate the exponential function at x = 25.4 and x = 0.25.
Solution
1) Click the y= button.
2) Hit the Clear button to erase any function entered.
3) Enter 2 and hit the ^ button and hit the X button .
4) Hit the Graph button to view the graph of y = 2 x .
5) To evaluate y = 2 x , hit the 2nd button and the graph button. Scroll to the x value and move to the y column to find the answer (i.e. x = 13).
6) To set the X values to what you want, hit the 2nd button and the Window button . Set the beginning value of 0, and the amount to increase the x value by 0.25 then hit the 2nd button then the Graph button.
Scroll down to x = 0.25 and move to the Y 1 value. The Y value is 1.1892071150027. Round it to the desired decimal places.
7) To set the table to ask you for a specific value. Hit the 2nd button and the Windows key . Scroll down to Indpnt and highlight Ask then hit the enter button.
Then hit the 2nd button and the graph button. Enter 25.4 and hit enter button. Move over to the Y 1 column to see the answer.
Round to the desired decimal places.