The feeling of chest tightness may be caused by physiological reasons such as poor air circulation, or it may be caused by diseases such as endobronchial tumor or emphysema. 1. Physiological reasons: prolonged stay in a room with poor air circulation will easily cause chest tightness, which will make the patient feel that there is always a blockage of breath in the chest. 2. Pathologic causes: (1) Bronchial tumor: when there is a tumor in the bronchial tube, it will compress the bronchial tube, resulting in unsmooth breathing, which may also cause the manifestation of feeling that there is a blockage of breath in the chest. (2) Emphysema: the cause of emphysema is not yet clear. When the disease is serious, it will cause damage to the alveoli and respiratory bronchial tubes, causing the above symptoms. It may also be caused by other reasons, such as heart disease, asthma, etc. Patients should go to the hospital for treatment in time to prevent the condition from worsening.