There are more causes of heartburn, which may include heart disease, esophageal disease and psychosomatic factors and other diseases, and what is going on should be judged according to the accompanying symptoms and past medical history. Cardiac pain may be related to the following diseases: 1, cardiovascular system diseases: coronary heart disease (angina pectoris, heart attack, and pulmonary embolism can cause myocardial ischemia and hypoxia, causing sudden cardiac pain. Myocarditis, pericarditis and other infectious diseases may also cause heartburn. Coronary artery disease is associated with exertion and emotional excitement, which can be relieved by rest or nitroglycerin inhalation. Pulmonary embolism may be accompanied by symptoms such as hemoptysis and dyspnea. Viral myocarditis may be preceded by a history of upper respiratory tract infection. Cardiac pain in pericarditis is related to breathing or body position. Cardiac enzymes, troponin, electrocardiogram, echocardiogram, coronary CT, cardiac MRI or coronary angiogram may be used to definitively rule out cardiac problems. 2, digestive system diseases: gastroesophageal reflux disease, peptic ulcer and biliary tract diseases are possible. Diseases of the digestive system are affected by feeding and antacid therapy, etc. It can be clarified by gastrointestinal endoscopy or ultrasound and other examinations. 3. Psychosomatic factors: cardiac neurosis and psychological factors. Cardiac neurosis and psychological factors can be considered under the circumstance that no clear cause can be found even after careful examination. When sudden heart pain is found, cardiovascular system diseases must be ruled out first, because conditions such as heart attack and pulmonary embolism may lead to death if not treated in time. Regardless of the condition causing the sudden heartburn, the patient needs to be seen by a hospital as soon as possible to rule out critical cardiopulmonary disease.