If there is bloody discharge before menstruation, the most common clinical cause is progesterone insufficiency, and progesterone insufficiency will cause irregular shedding of the endometrium, which will lead to irregular vaginal bleeding before menstruation, and low progesterone will often be detected on the 2nd-3rd day of menstruation when blood tests are taken for sex hormone six. If other diseases are ruled out, such as endometrial inflammation, submucosal fibroids, and bleeding due to abnormal coagulation are ruled out, progesterone supplementation can be given, and progesterone capsules can be given orally after ovulation, and it is recommended that the medication be given for 3 menstrual cycles, which will improve the symptoms.