There are several common reasons why women bleed again after a few days of menstruation: the first reason may be due to gynecological inflammation, such as common endometritis, vaginitis, pelvic inflammatory disease, and tubal inflammation, etc. Among them, endometritis is the most common reason why women bleed again after a few days of menstruation. The second reason, for older women, is to suspect neoplastic diseases, such as, endometrial cancer, uterine plasma cancer, and vaginal rhabdomyosarcoma, etc. The third reason, the patient’s emotional instability and stress during menstruation triggers hormonal secretion disorder in the body. The fourth cause, irregular menstrual bleeding due to irregular menstruation. Other causes may be due to vaginal injuries, foreign bodies in the vagina, etc. Therefore, the causes are varied and need to be diagnosed and treated in a hospital.