Left rotator cuff injury can be treated by general treatment, physical therapy, medication and surgery. 1. General treatment: when the left rotator cuff injury occurs, attention should be paid to keep the shoulder at rest, there can be light activities, but need to prevent repetitive or strenuous activities, try to limit the range of motion of the left shoulder to prevent the injury from worsening. 2. Physiotherapy: local massage, acupuncture, hot and cold therapy, microwave physiotherapy, electrotherapy and other physiotherapy can help promote local blood circulation, reduce inflammation and edema, and relax the local muscles, so as to promote the recovery of left rotator cuff injury. 3. Drug therapy: When obvious pain symptoms appear due to left rotator cuff injury, non-steroidal anti-inflammatory and analgesic drugs such as diclofenac sodium and ibuprofen can be applied under the instruction of doctors to relieve the pain. If the symptoms are serious, local injection of dexamethasone, prednisolone and other corticosteroids can be used. 4. Surgery: If the effect of conservative treatment is not good, surgery can be considered, such as arthroscopic surgery, open surgery, etc., which is good for removing the necrotic rotator cuff tissues, and the locally damaged or ruptured tendons can be sutured and repaired to promote the recovery of rotator cuff injury. After the left rotator cuff injury occurs, should go to the regular hospital in time, after clear diagnosis of the cause, give targeted treatment.