Midnight lumbar pain recovering by itself during the day is clinically more common for the following reasons: 1, lumbar muscle strain, which is the most common clinical cause, due to prolonged bending, straining or sedentary, resulting in chronic cumulative injury to the lumbar muscles and aseptic inflammation of the lumbar fascia, this pain is characterized by relief after heat and activity, and will be aggravated by cold and prolonged rest. When resting for a long time at night, especially in the supine position, it is recommended to put a thin cushion on the part of the waist where the lumbar belt is tied, which will reduce the force on the lumbar muscles and relieve and alleviate the pain at night.2. Kidney, ureteral stones and urinary system stones can have pain at night but can be relieved during the day, which is related to the fact that less urine is produced due to not drinking water after sleeping at night. Also sleeping at night, the stones may compress the nerves, and during the day the position of the activity changes, the nerve compression is released and the pain is relieved.