Dysmenorrhea is a symptom that occurs in many women during menstruation, especially in women who have not yet had children. The main causes of dysmenorrhea are the following: 1. During menstruation, the pelvic cavity is in a state of congestion, which can irritate and cause stomach pain and back pain. 2. During menstruation, the body releases a large amount of prostaglandins, which can also cause pain under the stimulation of prostaglandins. 3. . 4. Pathologically, if there is endometriosis, adenomyosis or fibroids, it can also lead to more serious menstrual pain symptoms.