Menstruation, also known as a
period or
monthly, is the regular discharge of blood and
mucosal tissue from the
inner lining of the uterus through the
vagina. Up to 80% of women report having some symptoms prior to menstruation. Common symptoms include
acne, tender breasts, bloating, feeling tired, irritability, and mood changes. These symptoms interfere with normal life, and therefore qualify as
premenstrual syndrome, in 20 to 30% of women. In 3 to 8%, symptoms are severe.