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.

Causes

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

• A number of hormonal irregularities, the most common of which is related to psychological stress. Psychological stress can lead to a hormonal imbalance sufficient to cause amenorrhea.

• Medications affecting hormonal balance (ie, certain contraceptives)

• Chromosomal abnormalities

• Hermaphroditism (having both male and female reproductive organs)

• Pituitary tumor

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.

Symptoms

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.

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

• 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

• An ultrasound, which involves the use of high-frequency sound waves to view and examine the organs of the abdominal cavity

• Laparoscopy, which involves the 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

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

Prevention

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.

RESOURCES:

New York Methodist Hospital
http://www.nym.org/healthinfo/docs/101/doc101treatments.html

United States Department of Health and Human Services, National Women's Health Information Center
http://www.womenshealth.gov/faq/menstru.htm

United States National Library of Medicine
http://www.nlm.nih.gov/medlineplus/ency/article/001218.htm#Treatment

University of Michigan Health System
http://www.med.umich.edu/1libr/aha/aha_amenor_crs.htm

CANADIAN RESOURCES:

BC Health Guide
http://www.bchealthguide.org

The Society of Obstetricians and Gynaecologists of Canada (SOGC)
http://www.sogc.org/index_e.asp

References:

Amenorrhea. Epigee Women's Health website.
Available at: http://www.epigee.org/menstruation/amenorrhea.html. Accessed September 14, 2006.

Amenorrhea: What you should know. American Academy of Family Physicians website. Available at: http://familydoctor.org/885.xml. Accessed September 14, 2006.