Pain under the chest usually has the following major categories of diseases: 1, heart disease: common acute myocardial infarction, coronary atherosclerotic heart disease, unstable angina pectoris, acute coronary syndrome, acute myocardial ischemia, cardiomyopathy, dilated cardiomyopathy, hypercardiosis and other conditions. 2, common lung diseases can be pleural effusion, pneumothorax, pneumonia, lung infections. 3, common diseases of the chest wall and the pleura can be Osteoarthritis, costochondritis and even herpes zoster can cause pain under the chest.4. Common diseases in gastroenterology include acute peritonitis, acute gastroenteritis, gastroduodenal reflux and other diseases, which can also cause pain under the chest.5. Mastitis, mammary tumors, and mammary hyperplasia are common among women, which can also cause pain under the chest.