Menstruation is the most visible phase of the menstrual cycle and its beginning is used as the marker between cycles. The first day of menstrual bleeding is the date used for the last menstrual period …

Feb 27, 2012 · Menstruation — aka having your period — is when blood and tissue from your uterus comes out of your vagina. It usually happens once every month.

Jan 11, 2026 · Menstruation (or period) happens monthly. As the uterus sheds its lining, vaginal bleeding follows. Menstrual blood is made of blood and tissue.

Dec 10, 2025 · Periods, also known as menstruation, occur when your uterus sheds its lining, causing blood and mucus to discharge from the vagina. 1 This usually occurs once a month if you are not …

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: Menstrual phase. The …

Sep 4, 2025 · Menstruation is period bleeding, which is casually referred to as “having your period.” This happens monthly (for most females) during your fertile years, except during pregnancy.

Dec 9, 2022 · 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.

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 happen every 21 to …

Jan 13, 2025 · A menstrual cycle begins with the first day of your period, or menstruation [MEN-stroo-AY-shuhn] and starts over again when the next period begins. Throughout a monthly menstrual …

Apr 20, 2025 · The menstrual cycle is about four weeks long, starting on the first day of bleeding and ending when the next period begins. However, it can vary greatly when girls first starts their period.