The pain between the two chests actually describes the pain behind the sternum. There are more causes of this symptom, including coronary artery disease, myocarditis, pericarditis, pulmonary embolism, aortic coarctation, gastroesophageal reflux, bronchitis, pleurisy, etc. The diseases that may be associated with pain between the two chests are as follows: 1. Cardiovascular system diseases: coronary heart disease (angina pectoris, heart attack,, pulmonary embolism, aortic coarctation, etc. can cause myocardial ischemia and hypoxia, causing pain between the two chests. Myocarditis, pericarditis and other infectious diseases may also cause pain between the two chests. Coronary artery disease is associated with exertion and emotional excitement, which can be relieved by rest or nitroglycerin inhalation. Pulmonary embolism may be accompanied by symptoms such as hemoptysis and dyspnea. Pain in aortic coarctation manifests as sudden tearing-like or knife-like pain. Viral myocarditis may be preceded by a history of upper respiratory tract infection. Cardiac pain in pericarditis is related to breathing or body position. Cardiovascular problems can be definitively excluded by cardiac enzymes, troponin, electrocardiogram, echocardiogram, coronary CT, aortic CT, cardiac MRI or angiography. 2, digestive system diseases: gastroesophageal reflux disease, peptic ulcer and biliary tract diseases are possible. Diseases of the digestive system are affected by feeding and antacid therapy, etc. It can be clarified by gastrointestinal endoscopy or ultrasound and other examinations. 3, respiratory system diseases: bronchitis, bronchial lung cancer, tuberculous pleurisy may cause pain between the two chests. The degree of pain mostly varies with breathing and coughing. 4.Psychological factors: cardiac neurosis and psychological factors. Cardiac neurosis and psychological factors can be considered under the circumstance that no clear cause can be found even after careful examination. If you find pain between the two chests, you must first exclude cardiovascular system diseases, because heart attack and pulmonary embolism may lead to death if not handled in time. Regardless of which condition causes the sudden pain between the two chests, the patient needs to be seen by a hospital as soon as possible to rule out critical cardiopulmonary disease.