The causes of chest tightness and lack of oxygen may be cardiovascular diseases, respiratory diseases, mental and psychological diseases. 1. Cardiovascular diseases: including long-term hypertension, diabetes mellitus patients, will be accompanied by myocardial ischemia, as well as cardiac insufficiency, cardiopulmonary imbalance, pulmonary hypertension, etc., will produce chest tightness and lack of oxygen. 2. Respiratory diseases: such as long-term chronic bronchitis, emphysema patients, chronic disease will change the airway or pleural cavity occupation, triggered by tuberculous pleurisy, there will be chest tightness, hypoxia symptoms. 3. Spiritual and psychological diseases: such as menopause, anxiety disorders and other spiritual and psychological disorders, can cause neurological dysfunction, can also appear obvious chest tightness, lack of oxygen feeling. If prolonged chest tightness and lack of oxygen, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment under the guidance of the doctor.