Shoulder pain at night may be caused by overwork, cervical spondylosis, periarthritis of the shoulder and other reasons. 1. Overexertion: patients due to overwork during the day, shoulder and neck muscle tension, resulting in muscle pain symptoms, in the night without timely relaxation of the muscles and thus the phenomenon of shoulder pain. 2. Cervical spondylosis: patients with cervical spondylosis due to a long time to maintain a posture, the cervical spine compression of the nerves, resulting in shoulder pain, in the evening due to the improper sleep posture, the intervertebral discs on the nerve root stimulation aggravated, radiating to the shoulder, thus appearing in the evening shoulder severe pain. 3. Periarthritis of the shoulder: Periarthritis of the shoulder is an inflammation of the soft tissues around the shoulder joint, and patients will experience shoulder pain, which is more obvious at night. When patients experience shoulder pain that is severe at night, it is recommended that they go to the hospital in time for diagnosis and treatment by a professional doctor.