menstruus

Menstruus is a term that refers to the monthly shedding of the uterine lining in humans and some other primates. This process, also known as menstruation or a period, is a normal biological function in individuals who are reproductively capable. It occurs when an egg released during ovulation is not fertilized. The uterine lining, which has thickened in preparation for a potential pregnancy, then breaks down and is expelled from the body through the vagina.

The menstrual cycle typically lasts around 28 days, though variations are common. The cycle is regulated by hormones, primarily estrogen and progesterone. Menstruation itself usually lasts between 3 to 7 days. During this time, individuals may experience various symptoms, including abdominal cramping, bloating, mood changes, and fatigue. These symptoms can range in severity from mild to more significant.

Menstruation is a sign of reproductive health and fertility. It begins at puberty, usually between the ages of 10 and 16, and continues until menopause, which typically occurs between the ages of 45 and 55. Throughout history and across cultures, menstruation has been viewed and managed in diverse ways, often influenced by social, religious, and economic factors. Access to menstrual hygiene products and education about menstruation remains a global health and equity issue.