Shoulder pain when lifting the arm may be caused by diseases of the shoulder joint itself and peripheral nerve compression. 1. Diseases of shoulder joint itself: Diseases of shoulder joint itself will lead to the damage of bone or soft tissue around shoulder joint, when lifting the arm, due to the pulling and stimulation of shoulder joint, the symptoms of shoulder pain may appear, such as rotator cuff injury, frozen shoulder, subacromial impingement syndrome, etc. In addition, trauma to the shoulder joint will also appear the above symptoms, such as dislocation of the shoulder joint, shoulder joint fracture and so on. 2. Peripheral nerve compression: If the peripheral nerve innervating the shoulder area is compressed, the nerve will be stimulated by pulling in the process of lifting the arm, and the symptom of shoulder pain may also appear, such as the common cervical spondylosis compression nerve, which may cause typical pain in the process of lifting the arm. Based on the symptoms of shoulder pain when the arm is lifted, sometimes it is not possible to accurately determine the cause, but also need to be combined with the characteristics of the medical history, other test results to make an accurate judgment, it is recommended to clarify the cause of the disease under the guidance of a doctor.