The pain of the left back of the chest after the fall is healed is mainly related to the stimulation of the surrounding tissues and abnormal nerve function, and the common causes include bone irritation, pleural adhesion and nerve injury. 1. Bone irritation: after the chest is fractured after the fall, some of the fracture will heal and the bone will be irregular, and the neighboring tissues will cause repeated friction and stimulation, which will lead to local pain. 2. Pleural adhesion: after trauma, the lung tissue and adjacent pleura will be damaged, resulting in local pleural adhesion, which will cause local mild pain. 3. Nerve injury: trauma causes intercostal nerve injury, after recovery, the nerve is not completely repaired, can also cause pain and discomfort. If the pain is not relieved, it is necessary to consult a doctor in time for observation and diagnosis of the condition, and then do standardized treatment.