There are three main common causes of menstrual itch, as follows: a. Patients usually have vaginitis: for example, they have trichomoniasis, bacterial vaginosis, vulvovaginal pseudomonal yeast disease, that is, they have mycobacterial vaginitis or aerobic vaginitis, which may lead to the recurrence of vaginitis due to blood loss and decreased immunity of women during menstruation. Second, do not pay attention to hygiene: If you do not change sanitary napkins or wear chemical fiber underwear for a long time during menstruation, cotton underwear is not changed for a long time, resulting in local impermeability of the pubic area, which can easily lead to vulvar itching after being bored for a long time, and sanitary napkin allergy can also lead to vulvar itching. Third, the wrong cleaning vulva: during the period of many women in order to keep the vulva clean, hygienic, often use care solution, cleaning solution frequent cleaning vulva, resulting in vulvar vaginal flora imbalance, inducing itching symptoms.