Pain in the left side of the chest after activity is seen for the following reasons: First, elderly patients with underlying hypertension, diabetes and other diseases are prone to spasm of the coronary arteries, and even also have coronary atherosclerosis, which can lead to the occurrence of myocardial ischemia after activity, so it can manifest as pain in the chest, which can also radiate to the back of the shoulder. In this case, the symptoms can be temporarily relieved by taking oral medication to dilate the coronary arteries. Secondly, for female patients, there are also some patients caused by costochondritis, which is a self-limiting disease and is considered to be related to the immunity of the body. It occurs in the anterior thorax, especially in the costal cartilage and the quadratus rib area, and can trigger an increase in local pain symptoms after activity or exertion, which can be relieved after rest or with oral pain medication.