Usually there is no fastest treatment for left shoulder pain. Left shoulder pain may be caused by frozen shoulder, cervical spondylosis, rotator cuff injury, etc. Patients can improve their condition through general treatment, medication and surgery. 1. Frozen shoulder: patients can take non-steroidal anti-inflammatory drugs, such as ibuprofen, acetaminophen, etc.; muscle relaxants, such as epirubicin hydrochloride, etc.; and proprietary Chinese medicines, such as Bone Marrow Capsules, Xianling Bone Bo Capsules, etc., as prescribed by the doctor for treatment. Patients who are ineffective in conservative treatment of frozen shoulder or whose condition is more serious can be treated with capsulotomy and arthroscopic shoulder arthrolysis to relieve the symptoms of left shoulder pain. 2. Cervical spondylosis: patients with cervical spondylosis should improve the bad life, do a good job of shoulder protection, etc., can follow the doctor’s instructions to take non-steroidal anti-inflammatory drugs, such as diclofenac, meloxicam, etc.; muscle relaxants, such as Clozoxazone, flupirtine, etc.; dehydrating agents, such as mannitol, etc.; nutritive nerve drugs. Such as methylcobalamin, etc. for treatment, and surgery can be considered for severe cases. 3. Rotator cuff injury: acute injury at the initial stage of local ice packs, can reduce local pain, swelling, can follow the doctor’s instructions to take non-steroidal anti-inflammatory drugs, such as nimesulide, ketoprofen, etc.; closed drugs, such as lidocaine, etc. for treatment, the effect of conservative treatment is not obvious, the patient can consider surgical treatment. Left shoulder pain may also have many reasons. It is recommended that patients seek timely medical examination to clarify the cause of the disease and targeted treatment. Actively cooperate with the doctor’s treatment, pay attention to maintain the affected limb in life, avoid excessive activity of the affected area, follow the doctor’s instructions for regular review.