Chest pain is a common subjective symptom, many diseases and factors can cause chest pain, chest pain does not necessarily suffer from coronary heart disease, angina pectoris. Angina pectoris is a clinical syndrome caused by insufficient coronary artery blood supply and acute temporary ischemia and hypoxia of the myocardium with episodes of chest pain or chest discomfort as the main manifestation, and its typical performance mainly includes five aspects: 1, the trigger: mainly spontaneous or exertional, exertional angina pectoris is mostly related to exertion, fatigue, excitement, full meals. 2, site and radiation: mainly located in the posterior sternum or precordial area, generally pain can be radiated to the pharynx, arm, the left arm ulnar side is more common. Some of them can be radiated to the upper abdomen, and a few of them are reported to be radiated to the side of the thigh. Patients are often afraid to continue activities due to the gradual increase of pain during the attack. 3, nature: can be posterior sternal pressure, tightness, burning or choking sensation general needle-like, knife-like or electric shock-like pain is not like angina pectoris. 4, duration: angina pectoris generally rarely exceeds 15 minutes, such as more than 30 minutes should be considered the possibility of acute myocardial infarction. 5, relief mode: can be relieved within 3 minutes after removing the trigger, rest or containing nitroglycerin. The site of angina attack and the nature of pain are often atypical, so it is easy to be confused with other conditions. For example, some angina attacks are not in the precordial region, but in the neck, dental bed, throat, back, shoulder, arm or abdomen. There are also patients with angina pectoris that can manifest as numbness, heaviness and other discomfort in the arms and wrists. In addition, since the site of chest pain mainly depends on the distribution of nociceptive nerves, any stimuli, such as hypoxia, inflammation, increased muscle tone, cancer infiltration, tissue necrosis and physicochemical factors, can cause chest pain. Generally speaking, sharp pinprick-like pains, especially those appearing in the left inframammary region, are often not manifestations of angina pectoris. Persistent tightness in the chest, which may be relieved by deep inspiration and ineffective with nitroglycerin, is often seen in cardiac neurosis. Very brief pains are also rarely caused by myocardial ischemia. In addition, angina pectoris is not unique to coronary artery disease, but can be present in aortic stenosis or insufficiency, anemia, idiopathic hypertrophic subvalvular aortic stenosis, and myocarditis. Coronary artery disease is not limited to coronary atherosclerosis, but can be caused by genetic and congenital malformations, trauma and collagen disease, as well as other inflammatory diseases of the blood vessels.