Chest tightness at rest and after exercise may be caused by cardiac neurosis, autonomic dysfunction and other reasons. 1. Cardiac neurosis: cardiac neurosis is generally associated with stress, tension and anxiety. After exercise can be properly adjusted, the mood becomes better, mood relaxation and pleasure, will also appear at rest chest tightness after exercise is good. 2. Autonomic dysfunction: Autonomic dysfunction can easily lead to chest tightness at rest and get better after exercise. Generally, the sympathetic nervous system in the body is abnormal, which affects the functioning of the heart. If the symptoms of chest tightness at rest and after exercise are not relieved for a long time, it is recommended to go to the hospital in time to find out the cause.