Cardiac pain may be caused by the following diseases: a. Angina pectoris, angina pectoris is a local pain caused by spasm of blood vessels and muscles in the blood supply area due to temporary ischemia of heart vessels, which is a pinprick-like pain that can radiate to the left shoulder and can be relieved by taking nitroglycerin tablets. Second, chest wall pain, chest wall pain is often referred pain, common are pulmonary inflammation spread to the pleura, mediastinal tumor growth to the pleura, costochondritis and other pleural lesions caused by referred pain. Third, reflux esophagitis, reflux esophagitis mostly occurs when eating too much, lying down or sleeping, often accompanied by a burning sensation in the chest, can be complicated by similar angina symptoms, bronchial asthma, hysterical globus, etc. Fourth, other diseases that cause inflammation of the heart and inflammation of the pleura.