Aunt refers to menstruation. Menstrual back pain may be caused by hormone secretion, pelvic congestion and other physiological reasons, may also be caused by lumbar spine disease and other pathological reasons, need to be specifically analyzed. 1. Physiological reasons: before menstruation, the pelvis will be congested and the secretion of prostaglandins will increase, leading to vasodilatation and smooth muscle contraction, and the lumbar nerves will be involved, resulting in low back pain. 2. Pathological reasons: If you suffer from herniated lumbar disc, lumbar back muscle sprain and other diseases, pelvic congestion during menstruation will aggravate the sensitivity of the nerves, and the symptoms of low back pain will also occur. There may be other reasons for back pain during menstruation, it is recommended to go to the regular hospital for examination and treatment under the guidance of the doctor, do not blindly use medication, so as not to delay treatment.