Itching before and after menstruation may be both mold and trichomonas, and may also be related to hygiene habits, external stimuli, local lesions of the vulva. 1. mycobacterial or trichomonas vaginitis: itchy before and after menstruation may be vaginitis, vaginitis will have vulvar itching performance, to determine whether it is mycobacteria or trichomonas, need to go to the hospital to do the test to determine which kind of leukorrhea, and then targeted treatment. 2. Hygiene habits: women should develop the habit of cleaning the vulva every day, change and wash the underwear, otherwise vaginal secretions, sweat and other stimuli, is likely to cause bacterial growth, resulting in itching before and after menstruation. 3. External stimulation: If women take contraceptive pills or wear chemical fiber underwear, it will also cause itching before and after menstruation. 4. Localized lesions on the vulva: If a woman has eczema or warts on the vulva, the vulva may itch before or after menstruation. There may be other reasons for itching before and after menstruation, so it is recommended to go to the hospital for a formal examination to clarify the cause.