Definition

Not having or missing a menstrual period is called amenorrhea. This condition is divided into two types:

• Primary amenorrhea—when an adolescent female has not yet begun menstruation by around age 16 years
• Secondary amenorrhea—when a woman who has previously menstruated misses three or more periods in a row

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

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Causes

Secondary amenorrhea is most commonly caused by pregnancy. In nonpregnant women, amenorrhea may result from a variety of factors, including an existing condition, lifestyle, emotional distress, hormonal irregularity, or medicine. 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
• 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)
• Medicines (eg, antidepressants, chemotherapy drugs, corticosteroids, certain birth control pills)
• Chromosomal abnormalities
• Hermaphroditism (having both male and female reproductive characteristics)
• Pituitary tumor
• Thyroid dysfunction
• Uterine scarring

Risk Factors

Women who eat a diet that does not provide sufficient caloric intake, exercise excessively, or suffer 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 by 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 menstrual periods.

If you experience any of these symptoms, do not assume that the cause of your amenorrhea is something serious. If you are sexually active, the first thing to do is to determine if you are pregnant. Then, see your doctor 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
• Progestin challenge test (taking progestogen for 7-10 days to trigger bleeding in order to determine if lack of estrogen 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 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

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

• Congenital birth defect—surgery may be needed
• Pituitary tumor—surgery, radiation therapy, or medicine may be needed
• Hormonal irregularity—hormonal therapy, including oral contraceptives, may be prescribed
• Weight related—A healthy caloric intake and a reasonable exercise routine usually restores hormonal balance and menstruation.
• Psychological distress—relaxation techniques (eg, deep breathing), therapy, and exercise may help to decrease stress

Prevention

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