The common clinical causes of pain on the left side of chest are as follows: a. Elderly female patients, if accompanied by malignant tumors on the left side of the breast, invading the muscle layer of the chest wall and nerves will cause local pain and discomfort, and some of the patients may even suffer from intractable neuropathic pain. It is suggested that patients should have the primary tumor resection and regional lymph node dissection as early as possible to remove the tumor cells in the body and reduce the pain and discomfort on the left side of the chest. Second, patients with coronary atherosclerotic heart disease, if in the case of exertion, strenuous exercise or systemic infection and other triggers, it will cause acute contraction of coronary blood vessels, manifested as myocardial infarction symptoms, the patient can appear in the left side of the chest severe pain, accompanied by the sense of frequency of death, at this time, it is necessary to improve the coronary arteriography examination as soon as possible, to make clear vascular pathology, and if necessary, the implantation of a stent to alleviate the symptoms of pain.