The causes of tightness in the left side of the rib cage are physiological and pathological, and the pathological causes include costochondritis, emphysema, etc. The treatments include medication such as anti-inflammatory drugs and surgical treatment. 1. Physiological factors: excessive physical exercise for a long time, such as push-ups, staying up late and not getting enough sleep, and excessive mental stress can lead to symptoms of tightness in the ribs. Appropriate physical exercise and a good routine can effectively relieve the symptoms. 2. Pathological factors: Costochondritis is caused by viral or bacterial infections, which can lead to the symptoms of tightness in the ribs. Medications such as ibuprofen can be used, and surgery can be performed to remove the diseased ribs if the condition is serious. Emphysema can be caused by airway destruction, which can lead to tightness in the ribs. Medications such as aminophylline and salbutamol may be used. In severe cases, surgical removal of diseased tissue or lung transplantation may be used. The choice of medication needs to be made under the guidance of a doctor. When patients experience discomfort, they should go to the hospital immediately.