Waking up with shoulder pain can be caused by sleeping pressure, over fatigue, shoulder injury, cold and other factors. 1. Sleeping compression: Incorrect sleeping posture and long-time compression of one shoulder can lead to shoulder soreness after waking up. 2. Excessive fatigue: The patient has performed a lot of shoulder activities the day before, which can cause fatigue of the muscles and tendons around the shoulder joint. Shoulder aches and pains may occur after a night’s sleep. 3. Shoulder injury: the shoulder joint is injured by pulling and other injuries, the degree of injury is small, may not feel at that time, but the internal edema may occur at night, and the shoulder will be sore after waking up. 4. Cold: patients do not cover their shoulders when they sleep, which makes the shoulder joint cold for a long time, resulting in shoulder pain after waking up.