bulimia nervosa bulimia nervosa bulimia nervosa, also known as simply bulimia, is an eating disorder characterized by binge eating followed by purging or fasting, and excessive concern with body shape and weight. this activity aims to expel the body of calories eaten from the binging phase of the process. binge eating refers to eating a large amount of food in a short amount of time. purging refers to the attempts to get rid of the food consumed. this may be done by vomiting or taking laxatives. bulimia nervosaother namesbulimialoss of enamel (acid erosion) from the inside of the upper front teeth as a result of bulimiaspecialtypsychiatry, clinical psychologysymptomseating a large amount of food in a short amount of time followed by vomiting or the use of laxatives, often normal weightcomplicationsbreakdown of the teeth, depression, anxiety, substance use disorders, suicidecausesgenetic and environmental factorsdiagnostic methodbased on person's medical historydifferential diagnosisanorexia, binge eating disorder, kleine-levin syndrome, borderline personality disordertreatmentcognitive behavioral therapymedicationselective serotonin reuptake inhibitors, tricyclic antidepressantprognosishalf recover over 10 years with treatmentfrequency3.6 million (2015) other efforts to lose weight may include the use of diuretics, stimulants, water fasting, or excessive exercise. most people with bulimia are at normal weight. the forcing of vomiting may result in thickened skin on the knuckles, breakdown of the teeth, and effects on metabolic rate and caloric intake which cause thyroid dysfunction. bulimia is frequently associated with other mental disorders such as depression, anxiety, borderline personality disorder, bipolar disorder, and problems with drugs or alcohol. there is also a higher risk of suicide and self-harm. bulimia is more common among those who have a close relative with the condition. the percentage risk that is estimated to be due to genetics is between 30% and 80%. other risk factors for the disease include psychological stress, cultural pressure to attain a certain body type, poor self-esteem, and obesity. living in a culture that commercializes or glamorizes dieting and having parental figures who fixate on weight are also risks. diagnosis is based on a person's medical history; however, this is difficult, as people are usually secretive about their binge eating and purging habits. further, the diagnosis of anorexia nervosa takes precedence over that of bulimia. other similar disorders include binge eating disorder, kleine–levin syndrome, and borderline personality disorder. signs and symptoms how bulimia affects the body the erosion on the lower teeth was caused by bulimia. for comparison, the upper teeth were restored with porcelain veneers. bulimia typically involves rapid and out-of-control eating, which may stop when the person is interrupted by another person or the stomach hurts from over-extension, followed by self-induced vomiting or other forms of purging. this cycle may be repeated several times a week or, in more serious cases, several times a day and may directly cause: chronic gastric reflux after eating, secondary to vomiting dehydration and hypokalemia due to renal potassium loss in the presence of alkalosis and frequent vomiting electrolyte imbalance can lead to abnormal heart rhythms, cardiac arrest, and even death esophagitis, or inflammation of the esophagus mallory-weiss tears boerhaave syndrome is a rupture in the esophageal wall due to vomiting oral trauma, in which repetitive insertion of fingers or other objects causes lacerations to the lining of the mouth or throata depiction of how bulimia is viewed russell's sign: calluses on knuckles and back of hands due to repeated trauma from incisors perimolysis, or severe dental erosion of tooth enamel swollen salivary glands (for example, in the neck, under the jawline) gastroparesis, or delayed gastric emptying constipation or diarrhea tachycardia or palpitations hypotension peptic ulcers infertility constant weight fluctuations are common elevated blood sugar, cholesterol, and amylase levels may occur hypoglycemia may occur after vomiting these are some of the many signs that may indicate whether someone has bulimia nervosa: a fixation on the number of calories consumed a fixation on an extreme consciousness of one's weight low self-esteem and/or self-harming suicidal tendencies an irregular menstrual cycle in women regular trips to the bathroom, especially soon after eating depression, anxiety disorders, and sleep disorders frequent occurrences involving the consumption of abnormally large portions of food the use of laxatives, diuretics, and diet pills compulsive or excessive exercise unhealthy/dry skin, hair, nails, and lips fatigue, or exhaustion as with many psychiatric illnesses, delusions can occur, in conjunction with other signs and symptoms, leaving the person with a false belief that is not ordinarily accepted by others. people with bulimia nervosa may also exercise to a point that excludes other activities. interoceptive people with bulimia exhibit several interoceptive deficits, in which one experiences impairment in recognizing and discriminating between internal sensations, feelings, and emotions. people with bulimia may also react negatively to somatic and affective states. concerning interoceptive sensitivity, hypersensitive individuals may not detect feelings of fullness in a normal and timely fashion and therefore are prone to eating more calories. examining from a neural basis also connects elements of interoception and emotion; notable overlaps occur in the medial prefrontal cortex, anterior and posterior cingulate, and anterior insula cortices, which are linked to both interoception and emotional eating. related disorders people with bulimia are at a higher risk to have an affective disorder, such as depression or general anxiety disorder. one study found 70% had depression at some time in their lives (as opposed to 26% for adult females in the general population), rising to 88% for all affective disorders combined. another study in the journal of affective disorders found that of the population of patients that were diagnosed with an eating disorder according to the dsm-v guidelines about 27% also suffered from bipolar disorder. within this article, the majority of the patients were diagnosed with bulimia nervosa, the second most common condition reported was binge-eating disorder. some individuals with anorexia nervosa exhibit episodes of bulimic tendencies through purging (either through self-induced vomiting or laxatives) as a way to quickly remove food in their system. there may be an increased risk for diabetes mellitus type 2. bulimia also has negative effects on a person's teeth due to the acid passed through the mouth from frequent vomiting causing acid erosion, mainly on the posterior dental surface. research has shown that there is a relationship between bulimia and narcissism. according to a study by the australian national university, eating disorders are more susceptible among vulnerable narcissists. this can be caused by a childhood in which inner feelings and thoughts were minimized by parents, leading to "a high focus on receiving validation from others to maintain a positive sense of self". the medical journal borderline personality disorder and emotion dysregulation notes that a "substantial rate of patients with bulimia nervosa" also have borderline personality disorder. a study by the psychopharmacology research program of the university of cincinnati college of medicine "leaves little doubt that bipolar and eating disorders—particularly bulimia nervosa and bipolar ii disorder—are related." the research shows that most clinical studies indicate that patients with bipolar disorder have higher rates of eating disorders, and vice versa. there is overlap in phenomenology, course, comorbidity, family history, and pharmacologic treatment response of these disorders. this is especially true of "eating dysregulation, mood dysregulation, impulsivity and compulsivity, craving for activity and/or exercise." studies have shown a relationship between bulimia's effect on metabolic rate and caloric intake with thyroid dysfunction. causes biological as with anorexia nervosa, there is evidence of genetic predispositions contributing to the onset of this eating disorder. abnormal levels of many hormones, notably serotonin, have been shown to be responsible for some disordered eating behaviors. brain-derived neurotrophic factor (bdnf) is under investigation as a possible mechanism. there is evidence that sex hormones may influence appetite and eating in women and the onset of bulimia nervosa. studies have shown that women with hyperandrogenism and polycystic ovary syndrome have a dysregulation of appetite, along with carbohydrates and fats. this dysregulation of appetite is also seen in women with bulimia nervosa. in addition, gene knockout studies in mice have shown that mice that have the gene encoding estrogen receptors have decreased fertility due to ovarian dysfunction and dysregulation of androgen receptors. in humans, there is evidence that there is an association between polymorphisms in the erβ (estrogen receptor β) and bulimia, suggesting there is a correlation between sex hormones and bulimia nervosa. bulimia has been compared to drug addiction, though the empirical support for this characterization is limited. however, people with bulimia nervosa may share dopamine d2 receptor-related vulnerabilities with those with substance use disorders. dieting, a common behaviour in bulimics, is associated with lower plasma tryptophan levels. decreased tryptophan levels in the brain, and thus the synthesis of serotonin, such as via acute tryptophan depletion, increases bulimic urges in currently and formerly bulimic individuals within hours. abnormal blood levels of peptides important for the regulation of appetite and energy balance are observed in individuals with bulimia nervosa, but it remains unknown if this is a state or trait. in recent years, evolutionary psychiatry as an emerging scientific discipline has been studying mental disorders from an evolutionary perspective. if eating disorders, bulimia nervosa in particular, have evolutionary functions or if they are new modern "lifestyle" problems is still debated. social media portrayals of an 'ideal' body shape are widely considered to be a contributing factor to bulimia. in a 1991 study by weltzin, hsu, pollicle, and kaye, it was stated that 19% of bulimics undereat, 37% of bulimics eat an average or normal amount of food, and 44% of bulimics overeat. a survey of 15- to 18-year-old high school girls in nadroga, fiji, found the self-reported incidence of purging rose from 0% in 1995 (a few weeks after the introduction of television in the province) to 11.3% in 1998. in addition, the suicide rate among people with bulimia nervosa is 7.5 times higher than in the general population. when attempting to decipher the origin of bulimia nervosa in a cognitive context, christopher fairburn et al.'s cognitive-behavioral model is often considered the golden standard. fairburn et al.'s model discusses the process in which an individual falls into the binge-purge cycle and thus develops bulimia. fairburn et al. argue that extreme concern with weight and shape coupled with low self-esteem will result in strict, rigid, and inflexible dietary rules. accordingly, this would lead to unrealistically restricted eating, which may consequently induce an eventual "slip" where the individual commits a minor infraction of the strict and inflexible dietary rules. moreover, the cognitive distortion due to dichotomous thinking leads the individual to binge. the binge subsequently should trigger a perceived loss of control, promoting the individual to purge in hope of counteracting the binge. however, fairburn et al. assert the cycle repeats itself, and thus consider the binge-purge cycle to be self-perpetuating. in contrast, byrne and mclean's findings differed slightly from fairburn et al.'s cognitive-behavioral model of bulimia nervosa in that the drive for thinness was the major cause of purging as a way of controlling weight. in turn, byrne and mclean argued that this makes the individual vulnerable to binging, indicating that it is not a binge-purge cycle but rather a purge-binge cycle in that purging comes before bingeing. similarly, fairburn et al.'s cognitive-behavioral model of bulimia nervosa is not necessarily applicable to every individual and is certainly reductionist. every one differs from another, and taking such a complex behavior like bulimia and applying the same one theory to everyone would certainly be invalid. in addition, the cognitive-behavioral model of bulimia nervosa is very culturally bound in that it may not be necessarily applicable to cultures outside of western society. to evaluate, fairburn et al..'s model and more generally the cognitive explanation of bulimia nervosa is more descriptive than explanatory, as it does not necessarily explain how bulimia arises. furthermore, it is difficult to ascertain cause and effect, because it may be that distorted eating leads to distorted cognition rather than vice versa. a considerable amount of literature has identified a correlation between sexual abuse and the development of bulimia nervosa. the reported incident rate of unwanted sexual contact is higher among those with bulimia nervosa than anorexia nervosa. when exploring the etiology of bulimia through a socio-cultural perspective, the "thin ideal internalization" is significantly responsible. the thin-ideal internalization is the extent to which individuals adapt to the societal ideals of attractiveness. studies have shown that young women that read fashion magazines