Amenorrhea refers to the absence of a menstrual cycle. Primary amenorrhea occurs if an adolescent female has not yet begun menstruation by around age 16 or so. Secondary amenorrhea describes a condition in which a woman who has previously menstruated on a regular basis misses three or more periods in a row. In the United States, amenorrhea affects between 2-5% of women.

Most females begin menstruating between the ages of 9-18, but age 12 is the average. Menstruation, or a menstrual period, refers to the monthly process in which the uterus sheds blood and tissue in preparation for pregnancy.

If a female has not started her menstrual period by age 16, a doctor should be contacted to determine the cause and prescribe any treatment that may be necessary.

Menstrual Flow

Menstrual Flow
© 2009 Nucleus Medical Art, Inc.


Secondary amenorrhea is most commonly caused by pregnancy. But in nonpregnant women, amenorrhea may result from a variety of factors, including an existing medical condition, lifestyle, emotional distress, hormonal irregularity, or medication. Every effort should be made to determine the exact cause. Specific causes of amenorrhea include:

  • Dramatic weight loss, particularly from drastic diets, eating disorders including anorexia]]> and ]]>bulimia]]> , or excessive exercise
  • Dramatic weight gain or morbid obesity
  • Malnourishment
  • Birth defects including lack of a uterus, vagina, or other reproductive organs
  • Medical conditions including ]]>cystic fibrosis]]> , ]]>Cushing's disease]]> , ]]>polycystic ovary]]> , or ]]>Prader-Willi syndrome]]>
  • Psychological stress—can lead to a hormonal imbalance sufficient to cause amenorrhea.
  • Medications—some antidepressants, chemotherapeutics, corticosteroids, certain contraceptives.
  • Chromosomal abnormalities
  • Hermaphroditism (having both male and female reproductive organs)
  • Pituitary tumor
  • Thyroid dysfunction
  • Uterine scarring


Risk Factors

Women who eat a diet that doesn’t provide sufficient caloric intake, exercise excessively, or suffer under considerable psychological distress are more likely to experience amenorrhea.

Women born with chromosomal or hormonal abnormalities, as well as those who suffer from certain chronic diseases, are also more likely to experience amenorrhea.


The main symptom of primary amenorrhea is the absence of a menstrual period in girls age 16 or older. The main symptom of secondary amenorrhea is three or more missed periods in a row in a woman who has previously had a regular period.

If you experience any of these symptoms, don’t assume that the cause of your amenorrhea is something serious. If you’re sexually active, the first thing to do is to determine if you’re pregnant. Then see your physician to get a proper diagnosis.


Your doctor will ask about your symptoms and medical history, and perform a physical exam.

Tests may include the following:

  • Pregnancy test
  • Blood work to determine hormone levels
  • Chromosome test to determine if any abnormalities exist
  • Urine test
  • Progestin challenge test (taking progestogen for 7-10 days to trigger bleeding in order to determine if lack of estrogens is responsible for amenorrhea)
  • CT scan of the head]]> —a type of x-ray that uses a computer to make pictures of structures of the head, brain, and skull
  • ]]>MRI (magnetic resonance imaging ) scan of the head]]> —a test that uses magnetic waves to make pictures of brain tissue
  • ]]>Ultrasound]]> —use of high-frequency sound waves to view and examine the organs of the abdominal cavity
  • ]]>Laparoscopy]]> —insertion of a thin tube affixed with a light and camera, along with other instruments, through a tiny incision in the abdominal wall

All or even most of these tests are rarely indicated.



Treatment for amenorrhea is dependent upon the cause of the condition:

  • Congenital birth defect—may be correctable by surgery
  • Pituitary tumor—treatments usually involve surgery or radiation therapy]]>
  • Hormonal irregularity—hormone therapy, including oral contraceptives, may cause menstruation to begin
  • Weight related—improved diet, including healthy caloric intake and a reasonable exercise routine usually restores hormonal balance and menstruation
  • Medical condition—if effective treatment is available, it may restore menstruation


Many cases of amenorrhea are unavoidable with the notable exceptions of pregnancy, eating disorders, and cases related to medications. Use effective contraception if you are sexually active and maintain a healthy body weight through a reasonable diet and exercise regimen. Seeking help during time of stress may also help prevent a bout of amenorrhea.