Period in medical terms generally refers to menstruation, some women feel the most pain on the first day of menstruation because the endometrium secretes more prostaglandins, which can cause dysmenorrhea, and with the discharge of menstrual blood, the endometrium secretes less prostaglandins, and the pain will ease or even disappear the next day. In addition, it may also be caused by eating cold and raw food before menstruation, or by not taking rest and exercising vigorously on the day of menstruation. Most women experience a certain amount of discomfort during their menstruation, called dysmenorrhea. Some are milder, while others are more severe, and can present with crampy abdominal pain on the first day, accompanied by vomiting or even fainting in severe cases. Dysmenorrhea can be divided into primary dysmenorrhea and secondary dysmenorrhea: 1. Primary dysmenorrhea: no organic lesions, when the first day of menstruation, prostaglandin levels are higher than before, so that the smooth muscle of the uterus is overly contracted, vascular spasm, resulting in uterine ischemia and hypoxia, and the lower abdomen and lumbosacral drop discomfort and uterine contraction pain. With the gradual reduction of prostaglandins during menstruation, the symptoms of pelvic congestion are gradually relieved and the pain will be relieved; 2. Secondary dysmenorrhea: Most of them are related to organic lesions, such as endometriosis, myometriosis and other diseases, which can also cause dysmenorrhea due to these pathological factors acting on the body. Women should pay special attention to rest and keep warm before and during menstruation, avoid tension and anxiety, do not eat cold, stimulating and chilly food, avoid strenuous exercise, and take painkillers such as ibuprofen when abdominal pain is unbearable. If secondary dysmenorrhea is caused by gynecological diseases, you should actively treat the primary disease, and the dysmenorrhea symptoms will generally improve after the primary disease improves.