The main reason for lumbago when menstruating is the following: 1, the pelvic cavity will be in a state of congestion when menstruating, the uterus may stimulate the retroperitoneum and cause lumbago if it is in a retroflexed and retroverted position. It is recommended to rest or lie on the bed during menstruation, and if the lumbago is serious, you can apply hot compresses or do physical therapy on the lumbar area, which will reduce the symptoms of lumbago. 2, because of inflammation, especially chronic inflammation of the cervix, when the inflammation reaches the sacral ligament, it will cause lumbago, which will be aggravated when menstruation comes. It is recommended to actively treat the local chronic inflammation of the cervix, which can be treated orally or vaginally by inserting drugs together, which will strengthen the efficacy and shorten the course of treatment.