It is not possible to have intercourse during menstruation because the body’s immunity decreases due to changes in hormone levels in the body, which can easily lead to diseases if care is not taken. During menstruation, the cervical opening is not open, and pathogens can travel up to the pelvis through the vagina during intercourse, leading to vaginitis, endometritis, pelvic inflammatory disease, and severe pelvic inflammatory disease can lead to infertility. The contraction of the uterus during intercourse may also lead to increased menstrual flow and prolonged menstruation, while the exfoliated endometrium may become ectopic outside the uterine cavity with the contraction of the uterus during intercourse, resulting in endometriosis, which may manifest as progressive and aggravated dysmenorrhea and even infertility. Secondary dysmenorrhea is more difficult to cure and affects conception. If medication is not effective, even surgery is required. Intercourse during menstruation may also lead to positive anti-sperm antibodies, resulting in immune infertility. During menstruation, it is important to pay attention to menstrual hygiene, keep the vulva clean and dry, and change sanitary napkins regularly.