Your menstrual cycle begins on the first day of your period. Your cycle prepares your body for a possible pregnancy. The average cycle lasts between 24 and 38 days.

Triggered by falling progesterone levels, menstruation (commonly referred to as a "period") is the cyclical shedding of the lining, and is a sign that pregnancy has not occurred. Each cycle …

Dec 5, 2025 · Menstrual cycle, recurring fluctuations in hormone levels that produce physical changes in the uterus and ovaries to prepare the female body for pregnancy. In adult women, …

If the egg does not become fertilized, the lining of the uterus (endometrium) is shed during menstruation. The average menstrual cycle lasts 28 days. The cycle starts with the first day of …

Apr 22, 2023 · What's typical? The menstrual cycle is counted from the first day of one period to the first day of the next. The cycle isn't the same for everyone. Menstrual bleeding might …

Apr 23, 2025 · Each menstrual cycle starts on the first day of a period (menstruation) and ends on the day before the next period. The length of the typical menstrual cycle is 28 days, but there …

Jan 13, 2025 · Throughout a monthly menstrual cycle, your body makes different amounts of chemicals called hormones to prepare for pregnancy. These changing hormone levels can …

Sep 4, 2025 · A menstrual cycle is a monthly process the female body goes through to prepare for pregnancy. Your brain and hormones (natural chemical messengers) tell your body how to …

Jul 29, 2025 · Understanding your menstrual cycle can help you know which phase of your cycle you’re in, learn what’s normal for you, and know when to talk to your doctor. Phase 1: …

Menstruation starts during puberty (the first period is called menarche) and stops permanently at menopause. (Menopause is defined as 1 year after the last menstrual cycle.) By definition, the …