Menstruation below the itch, may be caused by the problem of sanitary napkins, may also be caused by gynecological inflammation, specific as follows: 1, sanitary napkin problem: menstruation if women use a new sanitary napkin, below the itchy, this situation should be considered that may be caused by allergies with the sanitary napkin, or sanitary napkin is not in line with the hygiene of the conditions in this case need to hurry to change the sanitary napkin. In addition, some women because of menstruation sanitary napkin long time covered in the lower body, coupled with wearing clothes too tight, will lead to vulvar itching. 2, gynecological inflammation: some women if during menstruation mold or trichomoniasis infection, can also cause itching below. Therefore, if you find itchy menstruation, it is better to go to the hospital for examination and treatment after clear diagnosis.