Women usually do not show drowsiness during their periods because during their periods, many women may have pain in the lower abdomen, lumbosacral aches and pains, and may have anal swelling. Under the stimulation of these uncomfortable factors, women just may experience insomnia, instead of drowsiness. At the same time, women may experience vaginal discomfort during menstruation because of the intermittent flow of menstrual blood. During menstruation, women are often advised to rest in bed as much as possible. However, during menstruation, drowsiness is not usually noticeable, and insomnia may occur instead.