Left chest pain may be related to pleurisy, costochondritis, coronary heart disease and so on. 1. Pleurisy: the pleura is stimulated by bacteria or viruses and other factors to produce inflammation, chest pain occurs when the lesion site is on the left side of the chest, and when the condition is serious, it can be accompanied by coughing, chest tightness, shortness of breath, dyspnea and other symptoms. 2. Costal chondritis: the 2nd and 3rd rib cartilage is common, when the lesion site is on the left side of the rib cage, there will be pain on the left side, and the skin surface and subcutaneous tissue are normal. The pain can be aggravated by the activity of the upper limbs on the same side, coughing movement, lying on the side or exertion, and can be alleviated after rest. 3. Angina pectoris: Myocardial ischemia and hypoxia due to coronary artery stenosis caused by abnormal lipid metabolism in the body. It often occurs after activity or emotional excitement, and generally the left chest pain is pressing pain. Left chest pain can also be seen in other causes, it is recommended to consult a doctor in a timely manner, follow the doctor’s instructions for relevant examinations, with the help of the doctor to clarify the cause, and targeted treatment or treatment.