Shoulder pain occurs when you get up from sleep, 1. It is mainly due to strenuous exercise of the shoulder before going to sleep, producing a slight strain or strain, which can lead to a significant pain after going to sleep. The blood circulation is better during the day, so the inflammatory metabolites can be metabolized well, but at night when you sleep, the blood circulation slows down and the inflammatory metabolites accumulate, so you will feel very painful when you get up from sleep. 2. When you sleep at night, the shoulder joint stays in one position for too long, and the strain on the muscles and the surrounding soft tissues occurs, which will form a sterile inflammatory disease over time. The inflammatory metabolites will also stimulate the peripheral nerves and cause pain when you wake up. 3. Due to the degeneration and hyperplasia of the shoulder joint, the blood circulation will slow down at night due to the cold, and the hyperplasia and calcification will stimulate the surrounding tissues and cause more pain.