Symptoms can be divided into two categories. First, functional chest tightness, that is, no organic lesions of chest tightness, such as closed doors and windows, air circulation room, stay a long time or encounter some unpleasant things, or even with others in a verbal dispute, or in the climate of low barometric pressure, often produce chest tightness, fatigue feeling, and even have difficulty breathing. The second, pathological chest tightness. That is, there are organic lesions of chest tightness, chest tightness can not only be physiological, but also can be triggered by the occurrence of certain organs in the body disease. It can occur suddenly or slowly. Sudden onset of dyspnea is mostly caused by acute trauma or spontaneous pneumothorax, acute asthma, acute tracheal foreign body, acute heart attack, and acute pulmonary infarction. Slow-onset chest tightness is a long-lasting disease with a gradual worsening of symptoms. In children, chest tightness and dyspnea may indicate congenital heart disease or mediastinal tumors. Young people with chest tightness and dyspnea may have a direct pneumothorax, mediastinal tumor, or rheumatic heart valve disease. Chest tightness and dyspnea in the elderly suggests emphysema, coronary artery disease and so on.