Absence of a woman's monthly menstrual period is called amenorrhea.
Primary amenorrhea is when a girl has not yet started her monthly periods, and she:
Most girls begin their periods between ages 9 and 18. The average is around 12 years old. If no periods have occurred when a girl is older than 15, further testing may be needed. The need is more urgent if she has gone through other normal changes that occur during puberty.
Being born with incompletely formed genital or pelvic organs can lead to a lack of menstrual periods. Some of these defects include:
Hormones play a big role in a woman's menstrual cycle. Hormone problems can occur when:
Either of these problems may be due to:
In many cases, the cause of primary amenorrhea is not known.
A female with amenorrhea will have no menstrual flow. She may have other signs of puberty.
The health care provider will perform a physical exam to check for birth defects of the vagina or uterus.
The provider will ask questions about:
A pregnancy test will be done.
Blood tests to measure different hormone levels may include:
Other tests that may be done include:
Treatment depends on the cause of the missing period. Lack of periods that is caused by birth defects may require hormone medicines, surgery, or both.
If the amenorrhea is caused by a tumor in the brain:
If the problem is caused by a systemic disease, treatment of the disease may allow menstruation to begin.
If the cause is the bulimia, anorexia or too much exercise, periods will often begin when the weight returns to normal or the exercise level is decreased.
If the amenorrhea cannot be corrected, hormone medicines can sometimes be used. Medicines can help the woman feel more like her friends and female family members. They can also protect the bones from becoming too thin (osteoporosis).
The outlook depends on the cause of the amenorrhea and whether it can be corrected with treatment or lifestyle changes.
Periods are not likely to start on their own if the amenorrhea was caused by one of the following conditions:
You may have emotional distress because you feel different from friends or family. Or, you may worry that you might not be able to have children.
Call your provider if your daughter is older than 15 and has not yet begun menstruating, or if she is 14 and shows no other signs of puberty.
Reviewed By: John D. Jacobson, MD, Professor of Obstetrics and Gynecology, Loma Linda University School of Medicine, Loma Linda Center for Fertility, Loma Linda, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.