When Do Most Girls Get Their Period?

Most girls get their first period when they're around 12. But getting it any time between age 10 and 15 is OK. Every girl's body has its own schedule.

There isn't one right age for a girl to get her period.

What Causes a Period?

A period happens because of changes in hormones in the body. Hormones are chemical messengers. The ovaries release the female hormones estrogen and progesterone . These hormones cause the lining of the uterus (or womb) to build up. The built-up lining is ready for a fertilized egg to attach to and start developing. If there is no fertilized egg, the lining breaks down and bleeds. Then the same process happens all over again.

How Does Ovulation Relate to Periods?

Ovulation is the release of an egg from the ovaries. The same hormones that cause the uterus lining to build up also cause an egg to leave one of the ovaries. The egg travels through a thin tube called a fallopian tube to the uterus.

Do Periods Happen Regularly When Menstruation Starts?

For the first few years after a girl starts her period, it may not come regularly. This is normal at first. By about 2–3 years after her first period, a girl's periods should be coming around once every 4–5 weeks.

How Much Blood Comes Out?

It may look like a lot of blood, but a girl usually only loses a few tablespoons of blood during the whole period.

Will I Have Periods for the Rest of My Life?

When women reach menopause (around age 45‒55), their periods will permanently stop. Women also won't have a period while they are pregnant.

Looking Ahead

Periods are a natural, healthy part of a girl's life. They shouldn't get in the way of exercising, having fun, and enjoying life. If you have questions about periods, ask your doctor, a parent, health teacher, school nurse, or older sister.