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 increasingly abnormal and irregular or absent.

What causes amenorrhea?

There are several possible causes of amenorrhea, including:

Pregnancy. Females no longer ovulate when they're 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 woman hasn't started to menstruate by age 16, a birth defect, anatomical abnormality, or other medical condition may be suspected.
Eating disorder. Females 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's severely malnourished.
Overexercise or strenuous exercise. Many female 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. Females 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/care provider evaluating a female's medical history and a complete physical examination including a pelvic examination. A diagnosis of amenorrhea can only be certain when the physician/care provider 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 female miss at least three consecutive menstrual cycles, without being pregnant. Young women who haven't had their first menstrual period by age 15 should be evaluated promptly, as making an early diagnosis and starting treatment as soon as possible is very important.