It is not recommended to have intercourse on the first day of menstruation to avoid the reoccurrence of vaginal bleeding or secondary infections. Menstruation is the cyclical peeling and bleeding of the uterine lining under the influence of hormones secreted by the ovaries. On the first day of menstruation when the uterine lining has not fully recovered, intercourse may stimulate the uterus to contract and cause bleeding again. The first day of menstruation, the cervical opening is not completely closed, it is easy to cause female reproductive tract infection, so it is not recommended to have intercourse at this time, generally recommended in the menstrual clean 3 days before having intercourse. During menstruation, we should pay attention to personal hygiene, keep the vulva clean and dry, change underwear and sanitary products, increase diet and nutrition to increase body resistance, pay attention to warmth, but also to avoid overwork and stay up late to ensure adequate rest, prohibit coitus and tub baths.