Menstruation is the medical name for your monthly period. This is when blood and tissue from the lining of the uterus (womb) is shed through the vagina and out of the body.
Menstruation starts at puberty and it is stimulated by hormones that make a girl’s body able to become pregnant. This usually happens anytime between the ages of 9 and 16 years. Menstruation will recur about every 28 days (the menstrual cycle), unless interrupted by pregnancy, and will stop at menopause, which occurs at about 50 years of age.
There are a number of problems that can occur with menstruation ranging from mild to severe. More than half of all women will have cramps (dysmenorrhoea) during the first day or two of their period. Other problems include very heavy or long periods (menorrhagia) or no periods (amenorrhoea).