Shoulder pain may be caused by over-exercise, or it may be caused by frozen shoulder, rotator cuff injury, cervical spondylosis and other diseases. 1. Excessive exercise: If recent high-intensity exercise may lead to shoulder pain after exercise, usually caused by the accumulation of large amounts of local lactic acid, which is a normal phenomenon and can often be relieved after rest. 2. Frozen shoulder: the pathogenesis of frozen shoulder is not yet clear, and it is considered to be caused by synovitis and joint capsule fibrosis and other diseases. The main symptoms are shoulder pain, stiffness, muscle spasm and cold shoulder. 3. Rotator cuff injury: rotator cuff injury is mostly caused by indirect violence, which will cause shoulder pain, shoulder popping, localized swelling, limited shoulder joint movement and other symptoms. 4. Cervical spondylosis: Cervical spondylosis is mainly caused by long-term strain on the cervical vertebrae, osteophytes, herniated discs and other reasons. The main symptoms are neck pain, stiffness, back pain, and possibly radiating pain in the shoulder. If the symptoms persist, you should go to the hospital in time and standardize the treatment under the doctor’s guidance.