How the Menstrual Cycle Works
Your menstrual period is part of your menstrual cycle—a series of changes that occur to parts of your body (your ovaries, uterus, vagina and breasts) every 28 days, on average. Some normal menstrual cycles are a bit longer; some are shorter. The first day of your menstrual period is day one of your menstrual cycle. The average menstrual period lasts about five to seven days. A "normal" menstrual period for you may be different from what's "normal" for someone else.
Types of Menstrual Disorders
If one or more of the symptoms you experience before or during your period causes a problem, you may have a menstrual cycle "disorder." These include:
- abnormal uterine bleeding (AUB), which may include heavy menstrual bleeding, no menstrual bleeding (amenorrhea) or bleeding between periods (irregular menstrual bleeding)
- dysmenorrhea (painful menstrual periods)
- premenstrual syndrome (PMS)
- premenstrual dysphonic disorder (PMDD)