Coronary heart disease can only be diagnosed by a specialist based on the patient’s symptoms and signs, combined with electrocardiogram (ECG), cardiac ultrasound, coronary arteriography and laboratory results, and other ancillary tests, and the patient cannot test himself. 1. Electrocardiogram (ECG): ECG can be done during the onset of chest pain, chest tightness, etc. Most patients can find obvious insufficient blood supply to the myocardium, but a small number of patients’ ECG can be normal, and they need to check the ambulatory ECG, which is a 24-hour record of the ECG, to observe whether there is active cardiac ischemia or not. It is also possible to do exercise load test to observe whether there is any myocardial ischemia on the ECG when the patient is exercising under the detection of the doctor and the instrument. 2. Cardiac ultrasound: Coronary heart disease will have insufficient blood supply to the myocardium, which affects the function of the myocardium, and thus myocardial activity is more than normal myocardium. Acute myocardial infarction and ischemic heart disease can be observed through the cardiac ultrasound segmental ventricular wall motion abnormality, heart enlargement, reduced cardiac function and so on. 3. Coronary angiography: Through catheterization technology, we can directly check whether there is any stenosis in the blood vessels of the heart and to what extent it is stenosed, and we can dynamically observe whether there is any spasm of the coronary arteries. 4. Coronary artery CT: It is the most commonly used method to assess the presence or absence of coronary artery lesions, but it is limited in determining the degree of stenosis. It should be noted that coronary artery disease is a chronic disease in which the arteries supplying the heart are severely narrowed, resulting in insufficient blood supply to the heart muscle, and the symptoms of ischemia usually manifest themselves as chest tightness or chest pain associated with physical activity. If such symptoms occur, it is important to go to the hospital for relevant examinations.