The menstrual cycle is the series of changes a woman's body goes
through to prepare for a possible pregnancy. Most girls start having periods
between the ages of 11 and 15.
A girl who has not had her first period by age 15 has what is called
primary amenorrhea. This is different from infrequent or light menstrual
cycles, which are very common in normal in teenagers, particularly in the first
couple of years after menstruation begins. Primary amenorrhea is also different
than if a girl starts having periods, but then stops having periods for at
least 3 cycles.
Causes of primary amenorrhea include:
- Problems with the structure of the vagina, such
as skin covering the opening of the vagina (imperforate
hymen).
- Absence of or an abnormal pelvic organ, such as the uterus
or ovaries.
- Very low or very high body weight.
- Eating
disorders, such as
anorexia,
bulimia, or fad dieting.
- Intense
exercise.
- Stress.
- Malnutrition.
- Chronic
diseases, such as
diabetes,
anemia, congenital heart disease, or
thyroid disease.
- Inherited diseases, such
as
Turner syndrome.
- A condition that causes a
hormone imbalance that interferes with normal
ovulation (polycystic ovary
syndrome).
- Medicines or medical treatment in childhood that
may have damaged the ovaries, such as chemotherapy or radiation treatment for
cancer. Chemotherapy or radiation treatment in women may cause irregular
cycles.
If no problem can be found to explain why you are not having periods,
your doctor may prescribe birth control pills to help control your cycle. These
will also help keep your bones strong, reducing your risk for brittle bones
(osteoporosis). Your doctor also may prescribe calcium
supplements to help ensure that your bones stay healthy.
Girls who have not begun to develop breasts or pubic hair by age 14
may have an increased chance of having amenorrhea. If you have not begun having
periods by the time you are 15, call your doctor for an evaluation.
You can still become pregnant even though you are not menstruating.
Practice birth control if you do not wish to become pregnant.