Missed Menstrual Periods (Amenorrhea)

What is amenorrhea?

The absence of periods or menstrual flow is called amenorrhea. Amenorrhea may be either primary or secondary. Primary amenorrhea is not having menstrual periods by the age of 16. Secondary amenorrhea is the absence of 3 or more periods in a row in a woman who has had regular menstrual periods.

How does it occur?

Menstruation requires that the uterus, cervix (opening to the uterus), vagina, and ovaries be normal and healthy. The pituitary gland and the hypothalamus, both located in the brain, must also be functioning properly. A problem with any of these parts of the body may keep you from having a period.

Primary amenorrhea

The main cause of primary amenorrhea is late puberty. It is fairly common in girls who are very thin or very athletic. A women's body needs a certain amount of body fat in order to trigger the hormones to start the menstrual cycle. Sometimes primary amenorrhea results from a hormonal problem, such as hypothyroidism, or a genetic disorder, such as chromosome abnormalities.

In some cases, a woman may not start menstruating because of a birth defect. For example, a woman may not have a vagina or uterus. Or the vagina may not have an opening that allows menstrual blood to escape.

Secondary amenorrhea

The most common cause of secondary amenorrhea is pregnancy. Sometimes a breast-feeding mother may not have menstrual periods. Periods may also take 3 months or longer to resume after a woman stops taking birth control pills or stops nursing.

Secondary amenorrhea may also result from:

an ovary that stops working before menopause
emotional stress
brain injury
tumor in the brain (pituitary gland), ovary, or adrenal gland, or a cyst in the ovary
pseudocyesis (when a woman is convinced she is pregnant, but is not)
depression
thyroid problems, such as on underactive or overactive thyroid gland
malnutrition
polycystic ovary
vigorous exercise, such as daily or long-distance running
increased production of the hormone prolactin by the pituitary gland
drugs, such as tranquilizers and antidepressants
rapid weight gain or loss
chemotherapy
chronic illness (for example, kidney failure, cystic fibrosis, and colitis)
radiation therapy (especially in the pelvic area)
Asherman's syndrome, which is scarring of the lining resulting from an infection or surgery such as a D&C (dilation and curettage)
heavy smoking, in some cases.

Long lapses between periods, lasting 6 months or longer, are common with ongoing physical stress. This is particularly the case if you have lost a lot of weight, as with anorexia. It may also happen if you have little or no body fat, as is true for some women athletes.

Permanent secondary amenorrhea occurs after menopause. Most women go through menopause between ages 45 and 55. Sometimes menopause occurs earlier, even before the age of 40. Periods also stop after a hysterectomy (surgical removal of the uterus).

What are the symptoms?

Not having menstrual periods is a symptom, not a disease. Other symptoms depend on what is causing the amenorrhea. For example, if you have a hormone imbalance, you may have a lot of body and facial hair, acne, breast milk secretions, a change in voice or sex drive, weight gain, or weight loss.

How is it diagnosed?

Though rarely due to a life-threatening cause, amenorrhea can be a fairly complicated problem. It takes time and working closely with your health care provider to diagnose the cause and to treat it.

Your provider will ask about your medical history and give you a thorough physical exam, including a pelvic exam. Your provider may order blood tests, x-rays, ultrasound scans, CT scans, or chromosome studies.

How is it treated?

The treatment depends on the cause. If you have no other symptoms or signs besides the absence of periods, you may not need treatment. If you are overweight, a diet and exercise program may restore your menstrual periods. Learning to manage stress at school or work and decreasing excessive physical exercise may also help.

In some cases your provider may prescribe birth control pills or other forms of hormones to restore hormone balance.

Surgery may be necessary if you have tumors or cysts in your ovaries or uterus. You may also need surgery if your vagina is shaped abnormally or has no opening.

How long will the effects last?

Amenorrhea after a hysterectomy or menopause is permanent.

Amenorrhea after you stop taking birth control pills usually lasts for 6 to 8 weeks, but it may last a year or longer.

If unusual stress or an illness has temporarily interrupted the hormone cycle, your periods should start again naturally, although how long you will go without periods cannot be predicted.

Untreated amenorrhea can result in decreased bone mineral density or osteoporosis, infertility, and other health problems.

How can I take care of myself?

If you miss more than 2 periods in a row, see your health care provider. Tell your provider about any medicine you are taking, both prescription and nonprescription.
If your periods are irregular, keep a record of the dates that they start, how long they last, the amount of menstrual flow, and any symptoms.
If you have no periods at all, try to remember and record when your last period occurred, how long it lasted, and the amount of menstrual flow.
Try to find out if there is any family history of a problem similar to yours.
Follow your provider's recommendations closely.

What can be done to help prevent amenorrhea?

To prevent amenorrhea from recurring, it is important to maintain a healthy lifestyle:

Make changes in your diet or activities to maintain a healthy weight.
Avoid excessive use of alcohol and mood-altering stimulants or sedative drugs.
Don't smoke.
Think about the areas of emotional stress and conflict in your life. If you feel that you cannot resolve these conflicts on your own, ask for help from family, friends, or health professionals.
Be moderate in all your activities. Try to balance your work, recreation, and rest.
Maintain a positive outlook. This problem can often be corrected.

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.

HIA File WOM5253F.HTM Release 9.0/2006