Shoulder pain when sleeping on the side is considered to be related to frozen shoulder, osteoarthritis or rotator cuff injury, which can be treated with medication, physical therapy or surgery according to the cause. 1. Frozen shoulder: non-steroidal anti-inflammatory drugs can be taken, such as diclofenac sodium delayed-release tablets or nimesulide capsules, local diclofenac diethylamide cream can be used externally, rehabilitation exercises, such as active and passive movement of the shoulder joint, to increase flexibility of the shoulder joint, and ultrasound physiotherapy can be performed. 2. Osteoarthritis: oral nutritional cartilage drugs, such as glucosamine sulfate capsule, can also be injected into the joint with sodium vitrate, infrared physiotherapy or ultrasonic physiotherapy. 3. rotator cuff injury: minor injuries, you can apply the blood and pain medication, such as Sanqi injury tablets or bones and tendons capsule, you can also apply magnetic therapy or heat therapy, if the injury is more serious, you can take arthroscopic ligament repair surgery. Side sleeping shoulder pain should go to the hospital in time to check the cause of the disease, and under the guidance of the doctor for treatment.