Amenorrhea
Amenorrhea is the absence of menstrual periods.
Some women never go through puberty, so periods never start. This disorder is called primary amenorrhea. In other women, periods start at puberty, then stop. This disorder is called secondary amenorrhea. Amenorrhea is normal only before puberty, during pregnancy, while breastfeeding, and after menopause.
Causes
Primary amenorrhea may be caused by a birth defect in which the uterus or fallopian tubes do not develop normally or by a chromosomal disorder, such as Turner syndrome (in which the cells contain one X chromosome instead of the usual two). Primary amenorrhea can also result from malfunction of the hypothalamus (a part of the brain), pituitary gland, or ovaries. Sometimes it results from malfunction of the thyroid gland (hyperthyroidism or hypothyroidism). Young women who are very thin, particularly those who have anorexia nervosa, may never menstruate.
Secondary amenorrhea can result from malfunction of the hypothalamus, pituitary gland, ovaries, thyroid gland, adrenal glands, or almost any part of the reproductive tract. Malfunction of these organs may result from a tumor, an autoimmune disorder, or use of certain drugs (including hallucinogenic drugs, chemotherapy drugs, antipsychotic drugs, and antidepressants). Cushing's syndrome and polycystic ovary syndrome (both of which involve hormonal abnormalities) may cause periods to stop or to be irregular. Other causes of secondary amenorrhea include a hydatidiform mole (a tumor that develops from an abnormal fertilized egg or the placenta) and Asherman's syndrome (scarring of the lining of the uterus resulting from an infection or surgery).
Stress due to internal or situational concerns can cause secondary amenorrhea, because stress interferes with the brain's control (through hormones) of the ovaries. Exercising too much or eating too little (as in anorexia nervosa) also affects the brain's control of the ovaries. Either behavior can cause the brain to signal the pituitary gland to decrease its production of the hormones that stimulate the ovaries. As a result, the ovaries produce less estrogen and periods stop.
Symptoms and Diagnosis
Amenorrhea may or may not be accompanied by other symptoms, depending on the cause.
Primary amenorrhea is diagnosed when periods have not started by age 16. Girls who have no signs of puberty by age 13 or who have not started having periods within 5 years of starting puberty are evaluated for possible problems.
Secondary amenorrhea is diagnosed when a woman of reproductive age (who is not pregnant or breastfeeding) has had no menstrual periods for at least 3 months. A physical examination can help doctors determine whether puberty occurred normally and may provide evidence of the cause of amenorrhea. But other procedures may be needed to confirm or identify the cause. Hormone levels in the blood may be measured. X-rays of the skull may be taken to look for a pituitary tumor. Computed tomography (CT), magnetic resonance imaging (MRI), or ultrasonography may be used to look for a tumor in the ovaries or adrenal glands.
Treatment
The underlying disorder is treated if possible. For example, a tumor is removed. Some disorders, such as Turner syndrome and other genetic disorders, cannot be cured.
If a girl's periods have never started and all test results are normal, she is examined every 3 to 6 months to monitor the progression of puberty. A progestin and sometimes estrogen may be given to start her periods and to stimulate the development of secondary sexual characteristics, such as breasts.
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