What Is It?
Amenorrhea is when a woman of childbearing age fails to menstruate. A woman normally menstruates every 23 to 35 days.
The part of the brain called the hypothalamus regulates the menstrual cycle. The hypothalamus stimulates the pituitary gland. The pituitary gland lies just below the hypothalamus at the base of the brain.
The pituitary gland releases two hormones that regulate the female reproductive cycle. They are luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
LH and FSH influence the production of estrogen and progesterone. These hormones control cyclic changes in the lining of the uterus. This includes 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.
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 is also called delayed menarche. It is most often due to late puberty.
This is fairly common in teenage girls who are very thin or very athletic. These young women are typically underweight. Their bodies have not experienced the normal puberty-related rise in body fat. This rise in body fat triggers the beginning of menstruation.
In other girls, the delay of menstruation may be caused by a genetic disorder. Or it may result from abnormal female reproductive organs.
Secondary amenorrhea occurs when a woman has experienced menstrual periods, but stops menstruating for three or more consecutive months.
Secondary amenorrhea can be caused by:
Pregnancy (the most common cause)
Menopause, the normal age-related end of menstruation
Emotional or physical stress
Rapid weight loss
Frequent strenuous exercise
Hormonal birth control methods, including birth control pills, the patch and long acting progesterone.
Polycystic ovary syndrome. This condition is associated with a tendency to be overweight, excessive body and facial hair and hormonal irregularities.
Premature ovarian failure (menopause before age 40)
Hysterectomy (surgical removal of the uterus)
Abnormal production of certain hormones, such as testosterone, thyroid and cortisone.
Tumors of the pituitary gland
Female athletes, especially young women, are more likely to have amenorrhea. Exercise itself does not cause amenorrhea. But it is more likely in women who exercise very intensely or who increase the intensity of their exercise rapidly.
Secondary amenorrhea occurs quite often in women who engage in activities associated with lower body weight, such as ballet and gymnastics.
Amenorrhea is a symptom in itself.
Any associated symptoms depend on the problem that is causing the amenorrhea.
For example, hormone imbalances may cause amenorrhea together with:
Excess body and facial hair
Lowering of the voice
Altered sex drive
Breast milk secretions
Your 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
Rapid weight changes
Obesity or extreme underweight
Your typical monthly menstrual patterns
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
Your doctor will review your medical history. He or she will do a general physical examination, followed by a thorough pelvic exam. Your doctor will check whether you are pregnant.
If your doctor suspects a specific cause, he or she will ask additional questions. For example, if your doctor suspects a hormonal abnormality, he or she may ask about:
Increased body hair
Extreme sensitivity to cold temperatures
Unusual breast secretions
If you are an athlete, your doctor will ask about your training program. This is particularly likely if you are underweight or have a low percentage of body fat.
The following tests may be done to identify the underlying cause of your absent periods:
Blood and urine tests. These can detect imbalances of female hormones. Imbalances may be caused by problems with the pituitary gland or ovaries. If problems are found, additional tests can be done. These will check whether your levels of thyroid and adrenal hormones are normal.
Pelvic ultrasound. This painless test uses sound waves. It can identify structural problems in your uterus and ovaries.
Progesterone challenge test. Your doctor may treat you with progesterone to see whether this initiates a menstrual period. If menstrual bleeding occurs, you are probably 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 FSH levels. FSH levels can help to determine whether your problem is in the ovaries or hypothalamus.
Additional testing may be necessary to pinpoint the cause of your missed periods. Diagnosing amenorrhea can be complicated. There are many potential causes.
In many teenagers with primary amenorrhea, puberty is late. But there is no permanent problem.
How long secondary amenorrhea lasts depends on the cause.
Pregnancy will stop a woman's menstrual periods until after childbirth.
A woman who stops taking birth control pills may not have a period for three months to a year.
Emotional or physical stress may cause amenorrhea for as long as the stress remains.
Rapid weight loss or gain, medications and chronic illness can cause missed periods.
Amenorrhea is permanent after menopause begins or after hysterectomy.
In many cases, teenage girls can help to prevent primary amenorrhea. They should follow a sensible exercise program. And they should maintain a normal weight.
Primary amenorrhea caused by anatomic abnormalities cannot be prevented.
You can prevent some forms of secondary amenorrhea. Take the following steps:
Eat a balanced 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.
Primary amenorrhea caused by late puberty usually does not need to be treated. The condition will go away on its own.
For primary amenorrhea caused by genetic abnormalities, treatment depends on the problem. For example, if the ovaries are not functioning properly, you may be given supplemental ovarian hormones. These will allow development of normal secondary sex characteristics such as breasts and pubic hair.
If amenorrhea is caused by a structural problem, surgery is usually necessary. For example, a vagina that doesn't have an opening may be surgically corrected.
Secondary amenorrhea may be due to menopause or a hysterectomy. In this case, your doctor will prescribe medications. They will help prevent complications of low estrogen levels.
For other forms of secondary amenorrhea, the treatment depends on the cause.
Stress. Your doctor may advise you to enroll in a stress-management course.
Obesity. Your doctor will outline a diet and exercise program to help you lose weight and improve overall fitness.
Excessive athletic training. Your doctor will recommend a more moderate program. This will help normal menstruation to start again.
Hormone imbalance. Your doctor may prescribe supplemental hormones.
Polycystic ovary syndrome. Multiple medical treatments can help regulate menstrual periods. These include metformin and cyclical use of female hormones.
Tumors in the ovaries, uterus or pituitary gland. Treatment depends on the type and location of the cysts or tumors. Surgery is sometimes necessary.
When to Call a Professional
You should contact your doctor if:
You are 14 and have not started to develop breasts or pubic hair
You are 16 and have not had your first menstrual period
If you are sexually active, call your doctor if you miss a period. 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
Your periods are irregular
In most instances, symptoms and conditions related to amenorrhea are reversible and treatable.
American College of Obstetricians and Gynecologists
P.O. Box 96920
Washington, DC 20090-6920
American Society for Reproductive Medicine
1209 Montgomery Highway
Birmingham, AL 35216-2809