MENSTRUATION
What is menstruation? Menstruation is the monthly shedding of the lining of your uterus. Menstruation is also known by the terms menses, menstrual period, menstrual cycle or period. Menstrual blood — which is partly blood and partly tissue from the inside of your uterus — flows from your uterus through your cervix and out of your body through your vagina. Menstruation is driven by hormones. Hormones are chemical messengers in your body. Your pituitary gland (in your brain) and your ovaries (part of your reproductive system) make and release certain hormones at certain times during your menstrual cycle. These hormones cause the lining of your uterus to thicken. This happens so that if a pregnancy would occur, an egg can implant into your uterine lining. Hormones also cause your ovaries to release an egg (ovulation). The egg moves down your Fallopian tubes, where it waits for sperm. If a sperm doesn’t fertilize that egg, pregnancy doesn’t occur. The lining of your uterus breaks dow...