Pain in the middle of the chest may be related to trauma, sternal lesions, upper gastrointestinal diseases, heart diseases, lung diseases, and mediastinal diseases. 1. Trauma: If the middle of the chest is injured by impact, the local soft tissues may be damaged and symptoms such as swelling and pain may occur. 2. Sternal lesions: costochondritis, sternal tumor (primary or metastatic tumor), leukemia and other diseases invading the sternum can cause pain and discomfort in the middle of both chests. 3. Upper gastrointestinal diseases: such as esophagitis, gastroesophageal reflux disease, esophageal tumors and other diseases, due to inflammation stimulation, acid reflux, tumor compression and other reasons, there will be pain in the middle of the chest. 4. Heart disease: angina attack, myocarditis, pericarditis, etc. because of myocardial ischemia, injury or inflammatory mediators stimulate the pericardium can cause pain and discomfort in the middle of both chests and precordial area. 5. Lung diseases: pleurisy, pneumonia, lung cancer and other diseases that stimulate the pleura or lung tissue can also cause pain in the middle of the chest. 6. Mediastinal diseases: thymoma, thymic carcinoma, lymphoma, thymic cyst and other diseases that cause masses to compress or invade the tissues behind the sternum can also cause pain in the middle of both chests. The causes of chest pain in the middle of the chest are more reasons, it is recommended that patients go to the hospital in time, to clarify the cause of the disease, under the guidance of the doctor for standardized treatment.