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Absence of Menstrual Periods

(Amenorrhea)

By

JoAnn V. Pinkerton

, MD, University of Virginia Health System

Reviewed/Revised Feb 2023
VIEW PROFESSIONAL VERSION
Topic Resources

Having no menstrual periods is called amenorrhea.

Amenorrhea is normal in the following circumstances:

  • Before puberty

  • During pregnancy

  • While breastfeeding

  • After menopause

At other times, it may be the first symptom of a serious disorder.

Amenorrhea may be accompanied by other symptoms, depending on the cause. For example, women may develop masculine characteristics (virilization), such as excess body hair (hirsutism Hairiness In men, the amount of body hair varies greatly (see also Overview of Hair Growth), but very few men are concerned enough about excess hair to see a doctor. In women, the amount of hair that... read more Hairiness ), a deepened voice, and increased muscle size. They may have headaches, vision problems, or a decreased sex drive. They may have difficulty becoming pregnant.

In most women with amenorrhea, the ovaries do not release an egg. Such women cannot become pregnant.

If amenorrhea lasts a long time, problems similar to those associated with menopause Menopause Menopause is the permanent end of menstrual periods and thus of fertility. For up to several years before and just after menopause, estrogen levels fluctuate widely, periods become irregular... read more Menopause may develop. They include hot flashes, vaginal dryness, decreased bone density (osteoporosis Osteoporosis Osteoporosis is a condition in which a decrease in the density of bones weakens the bones, making breaks (fractures) likely. Aging, estrogen deficiency, low vitamin D or calcium intake, and... read more Osteoporosis ), and an increased risk of heart and blood vessel disorders. Such problems occur because in women who have amenorrhea, the estrogen level is low.

Types of amenorrhea

There are two main types of amenorrhea:

  • Primary: Menstrual periods never start.

  • Secondary: Periods start, then stop.

Usually if periods never start, girls do not go through puberty, and thus secondary sexual characteristics, such as breasts and pubic hair, do not develop normally.

If women have been having menstrual periods, which then stop, they may have secondary amenorrhea. Secondary amenorrhea is much more common than primary.

Hormones and menstruation

Menstrual periods are regulated by a complex hormonal system Overview of the Female Reproductive System . Each month, this system produces hormones in a certain sequence to prepare the body, particularly the uterus, for pregnancy. When this system works normally and there is no pregnancy, the sequence ends with the uterus shedding its lining, producing a menstrual period Menstrual Cycle Menstruation is the shedding of the lining of the uterus (endometrium) accompanied by bleeding. It occurs in approximately monthly cycles throughout a woman's reproductive life, except during... read more . The hormones in this system are produced by the following:

  • The hypothalamus (part of the brain that helps control the pituitary gland)

  • The pituitary gland, which produces luteinizing hormone and follicle-stimulating hormone

  • The ovaries, which produce estrogen and progesterone

Other hormones, such as thyroid hormones and prolactin (produced by the pituitary gland), can affect the menstrual cycle.

Causes of Amenorrhea

Conditions that can cause amenorrhea include hormonal disorders, birth defects, genetic disorders, medications, and illicit drugs.

The most common reason for amenorrhea in women who are not pregnant or breastfeeding is

Table
  • Malfunction of any part of the hormonal system (hypothalamus, pituitary gland, and ovaries)

When this system malfunctions, the ovaries do not release an egg. The type of amenorrhea that results is called ovulatory dysfunction.

Amenorrhea can also result from conditions that affect the uterus, cervix, or vagina.

Less commonly, the hormonal system is functioning normally, but another problem prevents periods from occurring. For example, menstrual bleeding may not occur because the uterus is scarred (Asherman syndrome), because the cervix is narrowed (cervical stenosis), or because a birth defect blocks the flow of menstrual blood out of the vagina.

Which causes are most common depends on whether amenorrhea is primary or secondary.

Primary amenorrhea

The disorders that cause primary amenorrhea are relatively uncommon, but the most common are

Genetic disorders include

Genetic disorders and birth defects that cause primary amenorrhea may not be noticed until puberty. These disorders cause only primary amenorrhea, not secondary.

Secondary amenorrhea

The most common causes are

Pregnancy is the most common cause of amenorrhea among women of childbearing age.

The hypothalamus may malfunction for several reasons:

The pituitary gland may malfunction because

  • It is damaged by a disorder (such as a tumor) or a head injury.

  • Levels of prolactin are high.

Antidepressants, antipsychotic medications, oral contraceptives (sometimes), or certain other medications can cause prolactin levels to increase, as can pituitary tumors and some other disorders.

Less common causes of secondary amenorrhea include chronic disorders (particularly of the lungs, digestive tract, blood, kidneys, or liver), some autoimmune disorders, cancer, HIV infection, radiation therapy, head injuries, a hydatidiform mole (overgrowth of tissue from the placenta), Cushing syndrome, and malfunction of the adrenal glands. Scarring of the uterus (usually due to an infection or surgery), polyps, and fibroids can also cause secondary amenorrhea.

Evaluation of Amenorrhea

Doctors determine whether amenorrhea is primary or secondary. This information can help them identify the cause.

Warning signs

When to see a doctor

Girls should see a doctor within a few weeks if

  • They have no signs of puberty (such as breast development or a growth spurt) by age 13.

  • Periods have not started by 3 years after breasts begin to develop.

  • Periods have not started by age 15 in girls who are growing normally and have developed secondary sexual characteristics.

Such girls may have primary amenorrhea.

If girls or women of childbearing age have had menstrual periods that have stopped, they should see a doctor if they have

  • Missed 3 menstrual periods

  • Fewer than 9 periods a year

  • A sudden change in the pattern of periods

Such women may have secondary amenorrhea. Doctors always do a pregnancy test when they evaluate women for secondary amenorrhea. Women may wish to do a home pregnancy test before they see the doctor.

What the doctor does

Doctors first ask about the medical history, including the menstrual history. Doctors then do a physical examination. What they find during the history and physical examination often suggests a cause of amenorrhea and the tests that may need to be done (see table ).

For the menstrual history, doctors determine whether amenorrhea is primary or secondary by asking the girl or woman whether she has ever had a menstrual period. If she has, she is asked how old she was when the periods started and when the last period occurred. She is also asked to describe the periods:

  • How many days they lasted

  • How often they occurred

  • Whether they were ever regular

  • How regular they have been in the last 3 to 12 month

  • How heavy they were

  • Whether her breasts were tender or she had mood changes related to periods

If a girl has never had a period, doctors ask

  • Whether breasts have started to develop and. if so, at what age

  • Whether she has had a growth spurt and. if so, at what age

  • Whether pubic and underarm hair (signs of puberty) has appeared and. if so, at what age

  • Whether any other family member has had abnormal periods

This information enables doctors to rule out some causes. Information about delayed puberty and genetic disorders in family members can help doctors determine whether the cause is a genetic disorder.

Doctors ask about other symptoms that may suggest a cause and about use of medications (including prescription and over-the-counter medications, dietary supplements, and opioids), exercise, eating habits, and other conditions that can cause amenorrhea.

During the physical examination, doctors determine whether secondary sexual characteristics have developed. A breast examination is done. A pelvic examination Pelvic Examination For gynecologic care, a woman should choose a health care practitioner with whom she can comfortably discuss sensitive topics, such as sex, birth control, pregnancy, and problems related to... read more is done to determine whether genital organs are developing normally and to check for abnormalities in reproductive organs.

Doctors also check for symptoms that may suggest a cause such as

Table

Testing

In girls or women of childbearing age, testing may include

  • A pregnancy test

  • Blood tests to measure hormone levels

  • An imaging test or procedure to examine the reproductive system (such as ultrasonography or hysteroscopy)

  • Sometimes use of hormonal medications to determine whether they trigger a menstrual period

A pregnancy test is sometimes done even in girls who have not had a period or reported sexual activity. If pregnancy is ruled out, other tests are done based on results of the examination and the suspected cause.

If girls have never had a period (primary amenorrhea) and have normal secondary sexual characteristics, testing begins with hormonal blood tests, a physical examination, and ultrasonography to check for birth defects that could block menstrual blood from leaving the uterus. If birth defects are unusual or difficult to identify, magnetic resonance imaging (MRI) may be done.

Tests are usually done in a certain order, and causes are identified or eliminated in the process. If symptoms suggest a specific disorder, tests for that disorder may be done first. For example, if women have headaches and vision problems, MRI of the brain is done to check for a pituitary tumor. Whether additional tests are needed and which tests are done depend on results of the previous tests. Typical tests include

For hysteroscopy, doctors insert a thin viewing tube through the vagina and cervix to view the interior of the uterus. This procedure can be done in a doctor's office or in a hospital as an outpatient procedure.

For hysterosalpingography, x-rays are taken after a substance that can be seen on x-rays (a radiopaque contrast agent) is injected through the cervix into the uterus and fallopian tubes. Hysterosalpingography is usually done as an outpatient procedure in a hospital radiology suite.

Hormones (progestin or estrogen plus progestin) may be given by mouth to try to trigger menstrual bleeding. If the hormones trigger menstrual bleeding, the cause may be malfunction of the hormonal system that controls menstrual periods or premature menopause. If hormones do not trigger bleeding, the cause may be a disorder of the uterus or a structural abnormality preventing menstrual blood from flowing out.

Treatment of Amenorrhea

When amenorrhea results from a specific disorder, that disorder is treated if possible. With such treatment, menstrual periods sometimes resume. For example, if a woman has a hormonal disorder that can be treated, such as an underactive thyroid gland (hypothyroidism Hypothyroidism Hypothyroidism is underactivity of the thyroid gland that leads to inadequate production of thyroid hormones and a slowing of vital body functions. Facial expressions become dull, the voice... read more Hypothyroidism ), or an abnormality that is blocking the flow of menstrual blood and can be surgically repaired, her periods usually resume.

If a girl's periods never started and all test results are normal, she should see a health care practitioner every 3 to 6 months to check on the progression of puberty. She may be given a medication called progestin and sometimes estrogen to start her periods and to stimulate the development of secondary sexual characteristics, such as breasts.

Problems associated with amenorrhea may require treatment, such as

The effects of estrogen deficiency can be minimized by taking vitamin D, by consuming more calcium in the diet or in supplements, or by taking medications, including hormone therapy and medications that prevent bone loss, such as bisphosphonates Drugs Drugs or denosumab.

Rarely, girls have a genetic disorder that causes problems with hormonal function. Genetic disorders, such as Turner syndrome Turner Syndrome Turner syndrome is a sex chromosome abnormality in which girls are born with one of their two X chromosomes partially or completely missing. Turner syndrome is caused by the deletion of part... read more Turner Syndrome , cannot be cured. If women have a Y chromosome, doctors recommend surgical removal of both ovaries because having a Y chromosome increases the risk of ovarian germ cell cancer Ovarian Cancer, Fallopian Tube Cancer, and Peritoneal Cancer . Ovarian germ cell cancer starts in the cells that produce eggs (germ cells) in the ovaries.

Key Points

  • Various conditions can disrupt the complex hormonal system that regulates the menstrual cycle, causing menstrual periods to stop.

  • Doctors distinguish between primary amenorrhea (periods have never started) and secondary amenorrhea (periods started, then stopped).

  • The first test is usually a pregnancy test.

  • Unless a woman is pregnant, other testing is usually required to determine the cause of amenorrhea.

  • Problems related to amenorrhea (such as a low estrogen level) may also require treatment to prevent later health problems, such as fractures due to decreased bone density (osteoporosis).

Drugs Mentioned In This Article

Generic Name Select Brand Names
Crinone, Endometrin , First - Progesterone MC 10, First - Progesterone MC 5, Prochieve, PROMETRIUM
Calcidol, Calciferol, D3 Vitamin, DECARA, Deltalin, Dialyvite Vitamin D, Dialyvite Vitamin D3, Drisdol, D-Vita, Enfamil D-Vi-Sol, Ergo D, Fiber with Vitamin D3 Gummies Gluten-Free, Happy Sunshine Vitamin D3, MAXIMUM D3, PureMark Naturals Vitamin D, Replesta, Replesta Children's, Super Happy SUNSHINE Vitamin D3, Thera-D 2000, Thera-D 4000, Thera-D Rapid Repletion, THERA-D SPORT, UpSpring Baby Vitamin D, UpSpring Baby Vitamin D3, YumVs, YumVs Kids ZERO, YumVs ZERO
Prolia, XGEVA
NOTE: This is the Consumer Version. DOCTORS: VIEW PROFESSIONAL VERSION
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