Chest tightness and shortness of breath from smoking are mostly caused by chronic bronchitis, emphysema, and pulmonary pneumonia formed by long-term smoking. Therefore, you should quit smoking early, and then do some activities and physical exercise, such as exercising tai chi to soothe the lung disease and make the lung function improve. Therefore, quitting smoking is very useful for emphysema patients to partially restore lung function. If you continue to smoke, it will further aggravate the emphysema, the pulmonary blisters will further increase, and in severe cases, respiratory failure will occur.