The great aunt is menstruation. Having sex after the onset of menstruation can lead to increased menstrual flow and increase the chance of inflammation. 1. Increased menstrual flow: Sex will cause uterine spasms and contractions, which will promote the stripping of the uterine lining, thus causing increased menstrual flow and prolonged menstrual period. 2. Increase the chance of inflammation: women’s body immunity is low during menstruation, the vagina and the outside world is connected to the presence of bacteria, sex may lead to a large number of bacteria in the local reproduction or retrograde into the cervix, uterine cavity, thereby increasing the incidence of vaginitis, pelvic inflammatory disease. Women who are menstruating are advised to avoid sexual intercourse, and also to keep warm, pay attention to rest, do not do too strenuous exercise, and maintain a happy mood. If women have symptoms such as heavy menstruation and dysmenorrhea, it is recommended that they go to the gynecology department of a regular hospital for consultation and active treatment under the guidance of a doctor after clarifying the cause of the disease.