Health Library

Amenorrhea

What is amenorrhea?

Amenorrhea is a menstrual condition characterized by absent menstrual periods for more than three monthly menstrual cycles. Amenorrhea may be classified as primary or secondary.

• primary amenorrhea - from the beginning and usually lifelong; menstruation never begins at puberty.

• secondary amenorrhea - due to some physical cause and usually of later onset; a condition in which menstrual periods which were at one time normal and regular become increasing abnormal and irregular or absent.

What causes amenorrhea?

There are several possible causes of amenorrhea, including the following:

• pregnancy
  Women no longer ovulate when they are pregnant, thus menstruation ceases temporarily.

• ovulation abnormality
  Ovulation abnormalities are usually the cause of very irregular or frequently missed menstrual periods.

• birth defect, anatomical abnormality, or other medical condition
  If a young woman has not started to menstruate by the age of 16, a birth defect, anatomical abnormality, or other medical condition may be suspected.

• eating disorder
  Women with anorexia nervosa (or simply anorexia) and/or bulimia nervosa (or simply bulimia) often experience amenorrhea as a result of maintaining a body weight that would be too low to sustain a pregnancy. As a result, as a form of protection for the body, the reproductive system "shuts down" because it is severely malnourished.

• overexercise or strenuous exercise
  Many young women athletes in training experience absent menstrual cycles due to low body fat content.

• thyroid disorder
  In many cases, an underactive thyroid gland (a condition called hypothyroidism in which the thyroid gland is producing insufficient amounts of the thyroid hormone) or an overactive thyroid gland (a condition called hyperthyroidism in which the thyroid gland secretes too much thyroid hormone - resulting in too much thyroid hormone in the bloodstream and overactivity of the body's metabolism) is responsible for the absent menstrual cycles.

• obesity
  Women who are obese often experience amenorrhea as a result of excess fat cells interfering with the process of ovulation.

How is amenorrhea diagnosed?

Diagnosis begins with a gynecologist evaluating a patient's medical history and a complete physical examination including a pelvic examination. A diagnosis of amenorrhea can only be certain when the physician rules out other menstrual disorders, medical conditions, or medications that may be causing or aggravating the condition. In addition, a diagnosis of amenorrhea requires that a woman has missed at least three consecutive menstrual cycles, without being pregnant. Young women who have not had their first menstrual period by the age of 15 should be evaluated promptly, as making an early diagnosis and starting treatment as soon as possible is very important.

Treatment for amenorrhea:

Specific treatment for amenorrhea will be determined by your physician based on:

• your age, overall health, and medical history

• extent of the condition

• cause of the condition (primary or secondary)

• your tolerance for specific medications, procedures, or therapies

• expectations for the course of the condition

• your opinion or preference

Treatment for amenorrhea may include:

• progesterone supplements (hormone treatment)

• oral contraceptives (ovulation inhibitors)

• dietary modifications (to include increased caloric and fat intake)

In most cases, physicians will induce menstruation in non-pregnant women who have missed two or more consecutive menstrual periods, because of the danger posed to the uterus if the non-fertilized egg and endometrium lining are not expelled. Without this monthly expulsion, the risk of uterine cancer increases.