Coronary artery disease is classified as insidious or asymptomatic coronary artery disease, angina pectoris, myocardial infarction, ischemic cardiomyopathy, and sudden death because it has different clinical phenotypes. It often manifests as chest pain, chest tightness, angina pectoris, arrhythmia, heart failure, etc. These symptoms are more serious. 1. Occult or asymptomatic coronary heart disease: no angina symptoms, but objective evidence of myocardial ischemia. 2. Angina pectoris: stable angina often manifests itself as pressure, tightness or constrictive chest pain after the sternal body, which usually lasts from a few minutes to more than ten minutes, and usually not more than half an hour. Angina attack can be seen when the heart rate increases, blood pressure increases, anxiety, cold skin or sweating. It is mostly induced by physical labor or emotional excitement. Unstable angina behaves similarly to stable angina, is more severe, lasts longer, and can occur at rest. Nocturnal or resting angina may occur. It is accompanied by sweating, nausea, palpitations or dyspnea. 3. Myocardial infarction: The performance of acute non-ST-segment elevation myocardial infarction is the same as that of unstable angina. Myocardial necrosis may also occur. Acute ST-segment elevation myocardial infarction is often characterized by severe and prolonged pain, fever, tachycardia, epigastric distension, nausea, arrhythmia, hypotension, shock, heart failure and so on. 4. Ischemic cardiomyopathy: congestive ischemic cardiomyopathy is manifested by angina pectoris, heart failure, arrhythmia, thrombus and embolism, etc. Restrictive ischemic cardiomyopathy is often manifested by exertional dyspnea, angina pectoris, activity limitation, pulmonary edema, etc. 5. Sudden death. When the above symptoms appear, please go to the hospital as soon as possible to avoid delay.