Angina pectoris manifests itself clinically as dullness, pressure, and tightness in the precordial region or retrosternal area of the heart after exertion or emotional excitement in patients. It can be accompanied by radiating pain, most often to the left shoulder, left upper arm or left lower jaw, or in some patients to the back pain, which lasts about a few minutes, often no more than half an hour, and the patient can relieve the symptoms by resting or taking nitroglycerin. The most common cause of angina is caused by insufficient blood supply to the coronary arteries supplying the heart. The most common cause of insufficient blood supply to the coronary arteries is stenosis of the coronary arteries, and these stenoses include stenosis caused by atherosclerosis of the coronary arteries, stenosis caused by spasm of the coronary arteries, and stenosis caused by myocardial bridges of the coronary arteries. In addition, intracoronary thrombosis and coronary artery entrapment can cause angina pectoris to occur. If angina persists without relief and worsens progressively, it is recommended to go to the hospital as soon as possible to prevent myocardial infarction from occurring. If necessary, coronary CT or coronary angiography should be performed to clarify the nature, extent and location of the coronary lesion and to decide whether the next treatment should be oral medication or further interventional treatment.