When arm pain occurs at night while sleeping, it is mainly due to two reasons: first, because during sleep, the arm does not appear to relax and rest, for example, when lying on the side, the upper limb located on the upper side will be in a state of internal retraction, as well as the lateral muscles are strained, which will lead to the muscle tissue of the arm area, which is continuously in a state of fatigue and tension, and is prone to local strain, resulting in inflammation. In particular, the arm position itself has some chronic sterile inflammatory lesions, after maintaining a posture for a long time, the continuous stimulation will lead to increased inflammation, which will lead to pain symptoms more obvious. Second, because the arm position is not in a warm state when sleeping, once it is cold, it will cause the muscle tissue to become very tight, and the blood vessels will contract because of the drop in temperature, resulting in a reduction in blood supply, which will make the local energy and electrolyte supply drop, and in addition, after the venous return flow drops, it will lead to the accumulation of metabolic products, which will lead to more obvious arm pain.