Swimming is not allowed during menstruation. Swimming may lead to infection of the reproductive system and may also cause menstrual discomfort or aggravate it, leading to prolonged periods and increased menstrual flow. Because the resistance of women decreases during menstruation, especially the reproductive system, it is easy to have the possibility of infection. The vaginal cervix is relatively open during menstruation, and bacteria and viruses can easily travel upward leading to an upstream infection. Also menstrual blood travels upward, which may lead to endometriosis. During menstruation, pay attention to changing sanitary napkins regularly, prohibit sexual intercourse, eat a light and hygienic diet, eat more iron-rich foods, and avoid eating cold, greasy and indigestible foods.