Elevating the legs while sleeping can help the lower limbs become edematous and the lumbar muscles become tense and uncomfortable for a short period of time, which can help the venous return and reduce the edema and swelling of the lower limbs, and can keep the muscles of the lumbar region in a relaxed state, which can help the recovery of the lumbar region. However, for night sleep, elevating the leg for a long time will lead to tension in the leg muscles, which will cause strain on the leg muscles, and the blood supply to the arteries will decrease after elevation, and sometimes the leg muscles feel uncomfortable and cold. And in the night sleep, not always supine, sometimes need to alternate between side and supine, the leg in supine elevated, if a long time, feel uncomfortable to side lying, it will produce excessive stretching of the surrounding muscles, resulting in great discomfort, affecting the quality of sleep.