The symptoms of insufficient blood supply to the heart are mostly chest tightness and chest pain, which can be relieved by resting or taking nitroglycerin. Insufficient blood supply to the heart refers to the conflict between coronary blood supply and myocardial blood demand due to various reasons, so that the coronary blood flow cannot meet the needs of myocardial metabolism. Causes of decreased myocardial blood supply and oxygen supply or increased myocardial oxygen demand may lead to the onset of symptoms of cardiac insufficiency. The typical site of this chest pain is behind the sternum, and it can radiate to the left chest, the back of the left shoulder, the front inner side of the left upper arm; it can also radiate to the neck, pharynx, jaw and head; the nature of the pain is typically pressure-like, mostly accompanied by significant chest tightness, and some patients have a sense of near death, which often forces patients to stop activities immediately. The symptoms are mostly triggered by the onset of symptoms, such as going upstairs, fast walking, exertion, full meal, cold, emotional excitement, etc. The symptoms can be relieved by quiet rest or nitroglycerin. Some patients have atypical symptoms, such as epigastric pain and subxiphoid discomfort. If the above symptoms of chest tightness and chest pain occur in a patient with a history of hypertension, hyperlipidemia, diabetes, smoking, obesity, etc., or if the patient usually smokes a lot and is obese, this situation should be highly suspected whether the chest tightness and chest pain is caused by insufficient blood supply to the heart. Patients should promptly go to a regular hospital for electrocardiogram or cardiac enzymes and other tests to rule out the possibility of insufficient blood supply to the heart.