additional tests are required to establish the diagnosis. in the emergency department the typical approach to chest pain involves ruling out the most dangerous causes: heart attack, pulmonary embolism, thoracic aortic dissection, esophageal rupture, tension pneumothorax, and cardiac tamponade. by elimination or confirmation of the most serious causes, a diagnosis of the origin of the pain may be made. often, no definite cause will be found and reassurance is then provided. risk scores the global registry of acute coronary events score and the thrombosis in myocardial infarction performed at time of admission may help stratify persons into low, intermediate and high risk groups for acute coronary syndrome. however these scores do not provide management guidelines for risk-stratified persons. the heart score, stratifies persons into low-risk and high-risk groups, and recommends either discharge or admission based upon the score. heart score criteria point value history highly suspicious +2 moderately suspicious +1 slightly suspicious 0 ecg significant st-depression +2 nonspecific repolarization disturbance +1 normal 0 age ≥ 65 +2 45-65 +1 ≤ 45 0 risk factors* ≥ 3 risk factors or history of atherosclerotic disease +2 1-2 risk factors +1 no risk factors known 0 troponin ≥ 3× normal limit +2 1-3× normal limit +1 ≤ normal limit 0 *include hypercholesterolemia, hypertension, diabetes mellitus, smoking, obesity cumulative score: 0-3: 2.5% risk of adverse cardiac event. patient's can be discharged with follow-up. 4-6: 20.3% risk of adverse cardiac event. patients should be admitted to the hospital for trending of troponin and provocative testing. ≥7: 72.7% risk of adverse cardiac event, suggesting early invasive measures with these patients and close coordination with inpatient cardiology. if acute coronary syndrome ("heart attack") is suspected, many people are admitted briefly for observation, sequential ecgs, and measurement of cardiac enzymes in the blood over time. on occasion, further tests on follow up may determine the cause. medical tests on the basis of the above, a number of tests may be ordered: an electrocardiogram (ecg) chest radiograph or chest x rays are frequently performed echocardiography can be useful in patients with known cardiac disease or aortic dissection ct scanning is used in the diagnosis of aortic dissection v/q scintigraphy or ct pulmonary angiogram (when a pulmonary embolism is suspected) blood tests: troponin i or t (to indicate myocardial damage) complete blood count electrolytes and renal function (creatinine) liver enzymes creatine kinase (and ck-mb fraction in many hospitals) d-dimer (when suspicion for pulmonary embolism is present but low) serum lipase to exclude acute pancreatitis management management of chest pain varies with the underlying cause of the pain and the stage of care. prehospital care chest pain is a common symptom encountered by emergency medical services. aspirin increases survival in people with acute coronary syndrome and it is reasonable for ems dispatchers to recommend it in people with no recent serious bleeding. supplemental oxygen was used in the past for most people with chest pain but is not needed unless the oxygen saturations are less than 94% or there are signs of respiratory distress. entonox is frequently used by ems personnel in the prehospital environment. however, there is little evidence about its effectiveness. hospital care hospital care of chest pain begins with initial survey of a person's vital signs, airway and breathing, and level of consciousness. this may also include attachment of ecg leads, cardiac monitors, intravenous lines and other medical devices depending on initial evaluation. after evaluation of a person's history, risk factors, physical examination, laboratory testing and imaging, management begins depending on suspected diagnoses. depending upon the diagnosis, a person may be placed in the intensive care unit, admitted to the hospital, or be treated outpatient. for persons with suspected cardiac chest pain or acute coronary syndrome, or other emergent diagnoses such as pneumothorax, pulmonary embolism, or aortic dissection, admission to the hospital is most often recommended for further treatment. outpatient care for people with non-cardiac chest pain, cognitive behavioral therapy might be helpful on an outpatient basis. a 2015 cochrane review found that cognitive behavioral therapy might reduce the frequency of chest pain episodes the first three months after treatment. for persons with chest pain due to gastroesophageal reflux disease, a proton-pump inhibitor has been shown to be the most effective treatment. however, treatment with proton pump inhibitors has been shown to be no better than placebo in persons with noncardiac chest pain not caused by gastroesophageal reflux disease. for musculoskeletal causes of chest pain, manipulation therapy or chiropractic therapy, acupuncture, or a recommendation for increased exercise are often used as treatment. studies have shown conflicting results on the efficacy of these treatments. a combination therapy of nonsteroidal anti-inflammatory drugs and manipulation therapy with at-home exercises has been shown to be most effective in treatment of musculoskeletal chest pain. epidemiology chest pain is a common presenting problem. overall chest pain is responsible for an estimated 6% of all emergency department visits in the united states and is the most common reason for hospital admission. chest pain is also very common in primary care clinics, representing 1-3% of all visits. the rate of emergency department visits in the us for chest pain decreased 10% from 1999 to 2008. but a subsequent increase of 13% was seen from 2006 to 2011. less than 20% of all cases of chest pain admissions are found to be due to coronary artery disease. the rate of chest pain as a symptom of acute coronary syndrome varies among populations based upon age, sex, and previous medical conditions. in general, women are more likely than men to present without chest pain (49% vs. 38%) in cases of myocardial infarction.