menstruations

Menstruation, or a period, is the regular shedding of the uterine lining (endometrium) through the vagina in people who have a uterus. It is part of the menstrual cycle, which is regulated by hormones and varies in timing and flow. Bleeding typically lasts 3 to 7 days and the average loss is about 30 to 80 milliliters, though there is a wide range of normal.

The menstrual cycle is driven by hormones including follicle-stimulating hormone (FSH), luteinizing hormone (LH), estrogen, and progesterone. It comprises four phases: the menstrual phase (bleeding), the follicular phase (estrogen rising and follicle development), ovulation (release of an egg), and the luteal phase (progesterone prepares the uterus for possible pregnancy). In a typical 28-day cycle, ovulation occurs around day 14, but many healthy cycles fall outside this pattern.

Symptoms vary widely. Common experiences include cramps, bloating, breast tenderness, fatigue, and mood changes. Some people have heavy bleeding (menorrhagia), very painful periods (dysmenorrhea), or irregular cycles, especially during adolescence or perimenopause.

Menstruation is a normal biological process, and most people do not require treatment. When symptoms are troublesome or bleeding is very heavy or prolonged, options such as analgesics (for pain) or hormonal therapies may help regulate cycles. Persistent irregularities or severe symptoms should be discussed with a healthcare provider. Menarche typically occurs in adolescence, and menopause marks the end of menstrual cycles, usually between ages 45 and 55.