What Is It?
Amenorrhea means that a woman of childbearing age fails to menstruate.
A woman normally menstruates every 23 to 35 days. The cycle is regulated by the portion of the brain called the hypothalamus, which also controls body temperature, appetite and blood pressure. The hypothalamus stimulates the pituitary gland (located near the base of the brain) to release two hormones that regulate the female reproductive cycle: luteinizing hormone and follicle-stimulating hormone. These hormones influence the production of the hormones estrogen and progesterone, which are responsible for cyclic changes in the lining of the uterus, including menstruation. In order for a woman to have regular menstrual cycles, her hypothalamus, pituitary gland, ovaries and uterus must be functioning properly. Her cervix and vagina must also have a normal anatomy for menstrual blood to pass through.
There are two types of amenorrhea:
Primary amenorrhea occurs when a woman has not had her first menstrual period (menarche) by age 16. This condition, also called "delayed menarche," is most often due to late puberty, which is fairly common in teenage girls who are very thin or very athletic. These young women are typically underweight, and their bodies have not experienced the normal puberty-related rise in body fat that triggers the beginning of menstruation. In other girls, the delay of menstruation may be due to Turner's syndrome, a genetic disorder involving the sex chromosomes, or to abnormal female reproductive organs.
Secondary amenorrhea happens when a woman who has menstruated previously fails to menstruate for three months. Secondary amenorrhea can be caused by:
Amenorrhea affects 2% to 5% of all women of childbearing age in the United States. Female athletes, especially young women, may be more likely to have amenorrhea. While exercise or physical activity itself does not cause amenorrhea, it is more likely to occur in women who exercise very intensely or who increase the intensity of exercise rapidly. Women who engage in sports associated with lower body weight, such as ballet dancing or gymnastics, are more likely to develop amenorrhea than women in other sports.
Symptoms
Amenorrhea is a symptom in itself. Any associated symptoms will depend on the problem that is causing the missed menstrual periods. For example, various forms of hormone imbalance may cause amenorrhea together with excess body and facial hair, acne, a lowering of the voice, an altered sex drive, breast milk secretions, weight gain, or several or all these symptoms.
Diagnosis
Your doctor will ask you about:
If your doctor is concerned about a specific cause of amenorrhea, such as a hormonal abnormality, he or she will ask additional questions about specific hormone-related symptoms, such as acne, increased body hair, extreme sensitivity to cold temperatures, dry skin, constipation, hair loss or unusual breast secretions. If you are an athlete, especially a runner, your doctor will ask you to describe your training program, particularly if your body fat is below 22% or if your weight is less than 80% of ideal.
Next, your doctor will review your medical history and do a general physical examination, followed by a thorough pelvic exam. Once your doctor has determined that you are not pregnant, he or she will try to identify the underlying cause of your absent periods. In many cases, this can be done with the following simple tests:
If these tests do not pinpoint the cause of your missed periods, additional specialized testing may be necessary. Diagnosing amenorrhea sometimes can be fairly complicated, since there are so many potential causes.
Expected Duration
In many teenagers with primary amenorrhea, puberty is late, but there is no permanent problem. For women with secondary amenorrhea, how long amenorrhea lasts depends on the cause. For example, pregnancy will stop a woman's menstrual periods until after childbirth, while a woman who stops taking birth control pills may not have a period for three months to a full year. Emotional or physical stress may block the release of luteinizing hormone, causing amenorrhea that lasts for as long as the source of stress remains. Rapid weight loss or gain, medications and chronic illness also can cause a woman to miss one or more periods. Amenorrhea is permanent after menopause begins or after hysterectomy.
Prevention
In many cases, teenage girls can help to prevent primary amenorrhea by following a sensible exercise program and by maintaining a normal weight for their height and age. Primary amenorrhea caused by anatomic abnormalities of the reproductive tract cannot be prevented. To prevent secondary amenorrhea that is related to diet, over-exercise or stress, you can take the following steps:
Treatment
Primary amenorrhea caused by late puberty usually does not need to be treated because the condition will go away on its own. For primary amenorrhea caused by certain genetic (inherited) abnormalities, treatment depends on the problem. For example, if a genetic defect prevents the ovaries from functioning properly, a young girl may be given supplemental ovarian hormones to allow her to develop normal secondary sex characteristics (breast development, pubic hair) and to prevent osteoporosis (bone-thinning disease), which can be caused by low estrogen levels. If amenorrhea is caused by a structural problem, such as a vagina that is an unusual shape or doesn't have an opening, surgery is usually necessary.
If you have secondary amenorrhea due to menopause or a hysterectomy, your doctor will prescribe medications to prevent osteoporosis and other complications of low estrogen levels. For other forms of secondary amenorrhea, the type of treatment depends on the cause:
When To Call a Professional
You should contact your doctor if you have reached your 14th birthday and have not started to develop breasts or pubic hair, or if you have reached your 16th birthday and have not had your first menstrual period.
If you are sexually active, call your doctor if you miss a period, since you will need to have a pregnancy test. If you are not sexually active, see your doctor if you have missed three consecutive menstrual periods, or if your periods are irregular.
Prognosis
Amenorrhea rarely is caused by a life-threatening condition. In most instances, symptoms and conditions related to amenorrhea are reversible and treatable.
Additional Info
American College of Obstetricians and Gynecologists
P.O. Box 96920
Washington, DC 20090-6920
Phone: 202-638-5577
http://www.acog.org/
American Society for Reproductive Medicine
1209 Montgomery Highway
Birmingham, AL 35216-2809
Phone: 205-978-5000
Fax: 205-978-5005
E-Mail: asrm@asrm.org
http://www.asrm.org/
