Shoulder pain from sleeping pressure is often seen in patients who have been lying on one side for a long time. The main reasons for this are as follows: 1. Excessive squeezing and stretching of the shoulder joint on one side due to side lying can cause damage to the ligaments and joint capsule. When the patient lies on his or her side excessively, the shoulder joint will be excessively internally retracted and internally rotated, and the joint capsule of the shoulder joint will be excessively stretched at this time. In addition, some of the tendons above the shoulder joint will impact and squeeze with the shoulder peak, which will lead to damage to the above structures and cause pain in the long run. 2. The blood supply to the shoulder joint becomes poor due to long-term side lying and squeezing. If the patient lies on his or her side for a long period of time and the shoulder joint is overflexed, the blood circulation in the area will deteriorate, which may result in ischemic damage to the above-mentioned structures and cause pain. 3. When the patient lies on his or her side excessively, the shoulder joint on one side will be shrugged, which will cause coldness in the area, and when the patient gets up the next morning, he or she will often show pain.