A to Z: Amenorrhea, Primary
Primary amenorrhea is when a girl does not start her period by age 15 or 3 years after she begins puberty.
More to Know
Causes of primary amenorrhea include pregnancy, hormone imbalances, stress, thyroid conditions, ovarian cysts, being too thin, and long-term illness. Girls who exercise intensively may miss periods if they don't get enough calories in their diet. Primary amenorrhea can have other causes, too, such as genetics or a problem with the way the reproductive organs developed.
Keep in Mind
Treatment may help periods start or return. Depending on the cause, this might include medication, stress reduction, dietary changes, or reducing excessive exercise. In a few instances, surgery might be recommended.
All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.