The menstruation after a hot bath is most common in the late menstrual period, the endometrium has basically shed, and then the local cleaning during the bath has been residual in the vagina of the old blood flushed out of the body, so there will be no menstruation after the bath, is a normal phenomenon does not require special treatment. During menstruation, it is important to avoid taking a tub bath because the cervical canal is open during menstruation and the reproductive tract is relatively more open to upstream infections of bacteria and viruses, which can easily lead to infection of the reproductive system. The main cause of endometriosis is secondary dysmenorrhea and the need to avoid sexual intercourse during menstruation.