Tightness of the mouth, but activity is good, first consider the patient may have lung disease, pleural disease, cardiac neurosis may exist. 1. Lung disease: Lung infection or trauma may cause tightness in the chest, which may improve slightly with activity. 2. Pleural disease: When there is inflammation of the pleura, tightness of the chest may occur, leading to tightness in the chest, which may be aggravated by coughing and alleviated by activity. 3. Cardiac neurosis: cardiac neurosis occurs when the patient is anxious and tense, it will also lead to chest tightness and pain and other abnormal sensations, and after the activity, when the emotion is no longer anxious and tense, the tightness of the symptom will be reduced. For the diagnosis of cardiac neurosis, it is necessary to exclude organic diseases and at the same time, combine with the patient’s mental state for diagnosis. Chest tightness may also be other diseases, it is recommended to consult a doctor in time.