What Is It?
Amenorrhea means that a woman of childbearing age fails to menstruate. The normal menstrual cycle ranges from 23 to 35 days. It is regulated by the hypothalamus, a portion of the brain that 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 female reproductive cycling: luteinizing hormone and follicle-stimulating hormone. These hormones, in turn, influence 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 be anatomically normal to allow the passage of menstrual flow.
There are two types of amenorrhea: primary amenorrhea (also called “delayed menarche”) and secondary amenorrhea.
Primary amenorrhea occurs when a woman has not had her first menstrual period (menarche) by age 16. Primary amenorrhea 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 is required to trigger the beginning of menstrual cycling. In other girls, the delay of menses may be due to Turner’s syndrome, a genetic disorder involving the sex chromosomes, or to a developmental abnormality of the 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:
- Pregnancy (the most common cause)
- Breastfeeding (lactation)
- Menopause (the normal age-related end of menstruation)
- Premature ovarian failure (menopause before age 40)
- Hysterectomy (surgical removal of the uterus)
- Stopping birth control pills
- Use of a long-acting progesterone, such as Depo-Provera, for birth control
- Tumors of the pituitary gland, especially prolactinomas
- Polycystic ovary disease (a condition that causes abnormal levels of estrogen, luteinizing hormone and other hormones)
- Endocrine disorders such as Cushing’s syndrome (in which there are very high levels of cortisol, an adrenal hormone) or hyperthyroidism (abnormally high levels of thyroid hormone)
- Emotional or physical stress
- Rapid weight loss
- Frequent strenuous exercise
- Chronic illness, such as colitis, kidney failure or cystic fibrosis
- Chemotherapy for cancer
- Cysts or tumors in the ovaries
Among the general population, amenorrhea currently affects 2 percent to 5 percent of all women of childbearing age. Female athletes, especially young women, may be more likely to suffer from amenorrhea. While exercise or physical activity itself does not cause amenorrhea, its likelihood increases with the intensity of exercise, and how quickly a woman increases physical activity. 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.
Amenorrhea is a symptom in itself. Any associated symptoms will depend on the underlying problem. 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.
As part of your diagnostic evaluation, the doctor will ask you about:
- The date of your last menstrual period
- Whether you are sexually active
- Your birth control methods
- Your pregnancy history
- Your eating habits and weight fluctuations (if you are overweight or extremely underweight)
- Your typical monthly menstrual patterns (regular cycles or irregular cycles)
- The age when your mother entered menopause (many mothers and daughters enter menopause at about the same age)
- The amount of stress in your life, and how you deal with it
- Your exercise regimen
- The types of medications you are taking
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 percent or if your weight is less than 80 percent of ideal.
Next your doctor will review your medical history and perform 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:
- Blood and urine tests — These can detect imbalances of female hormones that are related to abnormal functioning of the pituitary gland or ovaries. If abnormalities are found, additional tests can be done to check whether levels of thyroid and adrenal hormones are normal.
- Pelvic ultrasound — This painless test uses sound waves to assess any possible abnormalities in the structure of your uterus and ovaries.
- Progesterone challenge test — Your doctor may treat you with the hormone progesterone for a few days to see whether this is followed by menstruation. If menstrual bleeding occurs, your amenorrhea is probably related to anovulation, which means you are not releasing a mature egg in the middle of your menstrual cycle. If bleeding does not occur, your doctor will order blood tests to check your follicle-stimulating hormone levels. These levels can help to determine whether your underlying problem lies in the ovaries or hypothalamus.
If these tests do not pinpoint the cause of your amenorrhea, additional specialized testing may be necessary. Diagnosing amenorrhea sometimes can be fairly complicated, since there are so many potential causes.
The length of amenorrhea is linked to the type and cause. In many teenagers with primary amenorrhea, puberty is late, but there is no permanent abnormality. For women with secondary amenorrhea, the duration depends on the underlying 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 secondary amenorrhea that persists 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.
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 usually cannot be prevented.
To prevent secondary amenorrhea that is related to diet, over-exercise or stress, you can take the following steps:
- Eat a low-fat diet that meets your recommended daily nutritional needs.
- Exercise moderately, but not excessively, to maintain an ideal body weight and muscle tone.
- Find healthy outlets for emotional stress and daily conflicts.
- Balance work, recreation and rest.
- Avoid excessive alcohol consumption and cigarette smoking.
For primary amenorrhea caused by late puberty, treatment is not usually necessary because the condition resolves on its own with time. For primary amenorrhea caused by certain genetic abnormalities, treatment depends on the underlying 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, which can be caused by low estrogen levels. If amenorrhea is caused by a structural abnormality, such as a vagina that is unusually shaped or lacks 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:
- Stress — If emotional stress is the problem, your doctor may advise you to enroll in a stress-management course.
- Obesity — If obesity is triggering the condition, your doctor will outline a diet and exercise program aimed at helping you lose weight and improve overall fitness.
- Excessive athletic training — If strenuous training is interrupting your menstrual cycle, your doctor will recommend a more moderate program. This will help normal menstruation to resume. It also will also decrease your risk of conditions related to low levels of estrogen, such as osteoporosis, heart disease, infertility and thinning of the tissues lining the vagina.
- Hormone imbalance — If altered hormone levels are preventing ovulation (release of an egg from the ovary), your doctor may prescribe supplemental hormones.
- Tumors or cysts in the ovaries, uterus or pituitary gland — If cysts or tumors are causing amenorrhea, treatment depends on their type and location. Surgery is sometimes necessary.
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.
Amenorrhea rarely is caused by a life-threatening condition. In most instances, symptoms and conditions related to amenorrhea are reversible and treatable.
Diseases and Conditions Center
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.