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Pronunciations amenorrhea computed tomography dysmenorrhea hirsutism hydatidiform hypothalamus opioids osteoporosis pituitary polycystic polycystic ovary syndrome thalamus ultrasonography uterine uterus

Amenorrhea is the absence of menstrual periods.

• Menstrual periods may never start, or they may start, then stop.
• Amenorrhea may result from various disorders or drugs that disrupt any part of the complex hormonal regulation of the menstrual cycle.
• Symptoms, such as excess body hair, headaches, hot flashes, and vaginal dryness, may accompany amenorrhea depending on the cause.
• The diagnosis is based on the woman's menstrual history, but information about symptoms, a physical examination, and sometimes other tests are needed to identify the cause.
• The disorder causing amenorrhea is treated if possible.
• Adolescent girls who have never had a period may be given hormones to start 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.

Amenorrhea can also be classified based on other features:

• Whether an egg is released (ovulatory) or not (anovulatory)
• Where the abnormality occurs, such as the hypothalamus (which controls the hormones that regulate menstrual cycles), pituitary gland (which produces hormones that stimulate the ovaries), or ovaries (which produce the hormones that ultimately control menstrual cycles)
• What type of disorder is causing it—genetic, structural, hormonal, autoimmune, or something else

Amenorrhea also may indicate pregnancy (the most common cause of secondary amenorrhea) or be the first symptom of a serious disorder and should be evaluated.

Causes

Malfunction of any part of the complex hormonal system that regulates the menstrual cycle can cause amenorrhea. This system includes the hypothalamus, pituitary, ovaries, adrenal glands, and thyroid gland. Malfunction of these organs can cause primary or secondary amenorrhea, depending on when malfunction occurs. Various disorders (including genetic, hormonal, and autoimmune disorders), infections, tumors, injuries, radiation therapy, and drugs can cause malfunction.

Some conditions, such as the following, cause only primary amenorrhea:

• A birth defect of the uterus or fallopian tubes
• A chromosomal disorder, such as Turner's syndrome (in which the cells contain one X chromosome instead of the usual two)

In some genetic disorders, ovulation never begins, and puberty and secondary sexual characteristics do not develop normally.

Some conditions, such as the following, usually cause only secondary amenorrhea:

• Polycystic ovary syndrome (characterized by irregular or no periods, obesity, high levels of male hormones, and often cysts in the ovaries)
• Hydatidiform mole (a tumor that develops from an abnormal fertilized egg or the placenta)
• Asherman's syndrome (scarring of the lining of the uterus due to an infection or surgery)
• Use of certain drugs (including hallucinogenic drugs, cocaine, opioids, chemotherapy drugs, antipsychotic drugs, antidepressants, and oral contraceptives) by women who have already started having menstrual periods

Some other disorders and stress due to internal or situational concerns can cause either type of amenorrhea. Stress interferes with the brain's control (through hormones) of the ovaries. For example, exercising too much (or to excess) and eating disorders or underlnutrition (as in anorexia nervosa, starvation, or excessive dieting) 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 never begin or they stop. Psychiatric disorders, such as depression or obsessive-compulsive disorder, can also cause this stress.

Symptoms

Amenorrhea may or may not be accompanied by other symptoms, depending on the cause. Such symptoms may include acne, excess body hair (hirsutism), deepening of the voice, headaches, visual disturbances, hot flashes, vaginal dryness, and decreased sex drive.

If amenorrhea lasts a long time, it can cause problems usually associated with menopause, such as decreased bone density (osteoporosis) and an increased risk of heart and blood vessel disorders.

Diagnosis

Primary amenorrhea is diagnosed when periods have not started by age 16. Girls who have no signs of puberty (such as breast development, pubic hair, and a growth spurt) by age 13 or who have not started having periods within 5 years of starting puberty are evaluated for possible problems. For example, doctors try to determine whether any other family members have had delayed puberty or a genetic disorder.

Secondary amenorrhea is diagnosed when a woman of reproductive age (who is not pregnant, breastfeeding, or menopausal) has had no menstrual periods for at least 6 months whether periods had been regular or irregular previously. Sometimes, secondary amenorrhea is diagnosed if such a woman has had no menstrual periods for only 3 months if periods had been regular previously. Doctors ask about use of drugs, exercise and eating habits, and other conditions that can cause amenorrhea.

In girls who have signs of puberty and in women of reproductive age, pregnancy tests are done to rule out pregnancy.

A physical examination can help doctors determine whether puberty has occurred or has occurred normally. Doctors examine the breasts and check for signs of puberty, such as pubic and underarm hair. They do a pelvic examination to determine whether the genital organs are developing normally and to check for abnormalities.

Other tests may be needed to confirm or identify the cause:

• Hormone levels in the blood may be measured.
• Magnetic resonance imaging (MRI) of the brain may be done to look for a pituitary tumor.
• Computed tomography (CT), MRI, or ultrasonography may be used to look for a tumor in the ovaries or adrenal glands.
• Hormones (estrogen and a progestin) may be given to try to trigger bleeding. The response may help doctors determine whether the abnormality is in the uterus or in the pituitary or hypothalamus.

Treatment

The underlying disorder is treated if possible. For example, a tumor is removed. Some disorders, such as Turner's 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.

Women who wish to become pregnant may be given hormones to induce release of an egg (see Infertility: Treatment).

Problems associated with amenorrhea, such as osteoporosis or excess body hair, may require treatment.

Last full review/revision December 2008 by JoAnn V. Pinkerton, MD