Pain on the left breast is not necessarily angina pectoris. The most typical symptom of angina pectoris is that the patient develops a dull, squeezing, or tightening pain in the precordial area or the middle and lower part of the sternum after exertion or after emotional stress. This pain can be accompanied by radiation, often radiating to the left shoulder, left upper arm or left jaw position, and in some patients to the chest and back. The duration varies from a few minutes to half an hour, and rest or nitroglycerin can relieve the symptoms. However, a small number of patients with angina atypical site, or even manifested as toothache, shoulder pain, back pain, abdominal pain, etc., easy to be confused with other diseases, and need to further rely on auxiliary examination to clarify. For example, if the patient has pain on the left breast, it is necessary to further improve the breast ultrasound to exclude whether there is any problem in the local breast. In addition, chest CT, electrocardiogram, plate exercise test, and even coronary CTA or coronary angiography can be done to further evaluate whether there is coronary artery stenosis.