Knee pain in young people who sleep at night is mainly due to strain on the knee joint during the day, mostly due to frequent flexion and extension, contraction and excessive activity of the knee joint, resulting in strain on the muscles and surrounding soft tissues. During the daytime, when the blood supply is better, there is no significant pain and some inflammatory metabolites can be metabolized effectively; however, at night, due to reduced activity, the blood circulation slows down and some inflammatory metabolites cannot be metabolized effectively, which can stimulate the peripheral nerves and cause pain. In addition, because the night will maintain a posture for too long, will also lead to excessive tension and fatigue of the muscles or tendons and other soft tissues of these strained areas, which will also aggravate the strain around the location of the strain, will lead to this pain more obvious. Usually put a soft pillow on the back side of the knee to keep the knee joint in a relaxed state; when lying on your side, put a soft pillow between the knee joint and the calf to keep the muscles in this position in a relaxed state to get better, and you can apply a warm water bag to avoid getting cold, which can significantly reduce the symptoms.