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Absence of Menstrual Periods



JoAnn V. Pinkerton

, MD, University of Virginia Health System

Last full review/revision Feb 2021| Content last modified Feb 2021

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), 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 may develop. They include hot flashes, vaginal dryness, decreased bone density (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. 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. 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.

The most common reason for no menstrual periods in women who are not pregnant or breastfeeding is

  • Malfunction of any part of this hormonal system

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

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 or because a birth defect, fibroid, or polyp blocks the flow of menstrual blood out of the vagina.

High levels of prolactin, which stimulates the breasts to produce milk, can result in no periods.


Amenorrhea can result from conditions that affect the hypothalamus, pituitary gland, ovaries, uterus, cervix, or vagina. These conditions include hormonal disorders, birth defects, genetic disorders, and drugs.

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

  • A genetic disorder
  • A birth defect of the reproductive organs that blocks the flow of menstrual blood (such as an imperforate hymen)

Genetic disorders include

  • Turner syndrome
  • Kallmann syndrome
  • Overproduction of male hormones by the adrenal glands (congenital adrenal hyperplasia)
  • Genital disorders that result in ambiguous—neither male nor female—genitals (pseudohermaphroditism or true hermaphroditism)
  • Disorders that result in having a Y chromosome (which normally occurs only in males).

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

Sometimes puberty is delayed in girls who do not have a disorder, and normal periods simply begin at a later age. Such delayed puberty may run in families.

Secondary amenorrhea

The most common causes are

  • Pregnancy
  • Breastfeeding
  • Malfunction of the hypothalamus
  • Polycystic ovary syndrome
  • Premature menopause (primary ovarian insufficiency)
  • Malfunction of the pituitary gland or the thyroid gland
  • Use of certain drugs, such as birth control pills (oral contraceptives), antidepressants, or antipsychotic drugs

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

The hypothalamus may malfunction for several reasons:

  • Stress or excessive exercise (as done by competitive athletes, particularly women who participate in sports that involve maintaining a low body weight)
  • Poor nutrition (as may occur in women who have an eating disorder or who have lost a significant amount of weight)
  • Mental disorders (such as depression or obsessive-compulsive disorder)
  • Radiation therapy or an injury

The pituitary gland may malfunction because

  • It is damaged.
  • Levels of prolactin are high.

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

The thyroid gland may cause amenorrhea if it is underactive (called hypothyroidism) or overactive (called hyperthyroidism).

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.

Genetic disorders, such as Fragile X syndrome, may cause menstrual periods to stop early (premature menopause).


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

Warning signs

Certain symptoms are cause for concern:

  • Delayed puberty
  • Development of masculine characteristics, such as excess body hair, a deepened voice, and increased muscle size
  • Vision problems
  • An impaired sense of smell (which may be a symptom of Kallmann syndrome)
  • A milky nipple discharge that occurs spontaneously (that is, without the nipple's being squeezed or otherwise stimulated)
  • A significant change in weight

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 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 Some Causes and Features of Amenorrhea).

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 long they lasted
  • How often they occurred
  • Whether they were ever regular
  • 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
  • Whether she has had a growth spurt
  • Whether pubic and underarm hair (signs of puberty) has appeared
  • 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 drugs, 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 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

  • A milky discharge from both nipples: Possible causes include pituitary disorders and drugs that increase levels of prolactin (a hormone that stimulates milk production).
  • Headaches, hearing loss, and partial loss of vision or double vision: Possible causes include tumors of the pituitary gland or hypothalamus.
  • Development of masculine characteristics, such as excess body hair, a deepened voice, and increased muscle size: Possible causes include polycystic ovary syndrome, tumors that produce male hormones, and use of drugs such as synthetic male hormones (androgens), antidepressants, or high doses of synthetic female hormones called progestins.
  • Hot flashes, vaginal dryness, and night sweats: Possible causes include premature menopause, a disorder that causes the ovaries to malfunction, radiation therapy, and use of a chemotherapy drug.
  • Shakiness (tremors) with weight loss or sluggishness with weight gain: These symptoms suggest a thyroid disorder.

Some Causes and Features of Amenorrhea


Common Features†


Hormonal disorders

Hyperthyroidism (an overactive thyroid gland)

Warm, moist skin, difficulty tolerating heat, excessive sweating, an increased appetite, weight loss, bulging eyes, double vision, shakiness (tremor), and frequent bowel movements

Sometimes an enlarged thyroid gland (goiter)

Blood tests to measure thyroid hormone levels

Hypothyroidism (an underactive thyroid gland)

Difficulty tolerating cold, a decreased appetite, weight gain, coarse and thick skin, loss of eyebrow hair, a puffy face, drooping eyelids, fatigue, sluggishness, slow speech, and constipation

Blood tests to measure thyroid hormone levels

Pituitary disorders, including tumors that produce prolactin‡ and injuries

Vision problems and headaches, particularly at night

Sometimes production of breast milk in women who are not breastfeeding (galactorrhea)

Blood test to measure prolactin levels

MRI of the brain

Polycystic ovary syndrome

Development of masculine characteristics (such as excess body hair, a deepened voice, and increased muscle size)

Irregular or no menstrual periods, acne, excess fat in the torso, and dark, thick skin in the underarm, on the nape of the neck, and in skinfolds

Blood tests to measure hormone levels

Ultrasonography of the pelvis to look for abnormalities in the ovaries

Premature menopause

Symptoms of menopause, including hot flashes, night sweats, and vaginal dryness and thinning of vagina

Risk factors such as removal of the ovaries, chemotherapy, or radiation therapy directed at the pelvis (the lowest part of the torso)

Blood tests to measure levels of estrogen and other hormones

For women under 35, examination of chromosomes in a sample of tissue (such as blood)

Tumors that produce male hormones (androgens), usually in the ovaries or adrenal glands

Development of masculine characteristics, acne, and genitals that are not clearly male or female (ambiguous genitals)

CT, MRI, or ultrasonography

Structural disorders

Birth defects:

  • Cervical stenosis (narrowing of the passageway through the cervix)
  • Imperforate hymen (an abnormal hymen that completely blocks the vagina's opening)
  • Transverse vaginal septum (a wall of tissue across the vagina, which prevents menstrual blood from flowing out)
  • Absence of reproductive organs

Primary amenorrhea

Normal development of breasts and secondary sexual characteristics

Abdominal pain that occurs in cycles and bulging of the vagina or uterus (because menstrual blood is blocked and accumulates)

A doctor's examination

Hysterosalpingography (x-rays taken after a contrast agent is injected into the uterus and fallopian tubes) or hysteroscopy (insertion of a viewing tube through the vagina to view the uterus)

Asherman syndrome (scarring of the lining of the uterus due to an infection or surgery)

Secondary amenorrhea

Often repeated miscarriages and infertility

Sonohysterography (ultrasonography after fluid is infused into uterus), hysterosalpingography, or hysteroscopy

Sometimes if results are unclear, MRI


Secondary amenorrhea

Pain, vaginal bleeding, constipation, repeated miscarriages, and an urge to urinate frequently or urgently


Sometimes MRI if fibroids are difficult to view or look abnormal


Secondary amenorrhea

Vaginal bleeding

Ultrasonography, sonohysterography, or hysteroscopy

Conditions that cause the hypothalamus to malfunction

Chronic disorders, particularly disorders of the lungs, digestive tract, blood, kidneys, or liver

Symptoms related to the specific disorder

A doctor's examination

Usually various tests specific to the type of disorder

Excessive exercise

Often a low body weight and body fat

A doctor's examination

Infections, such as HIV infection, encephalitis, syphilis, and tuberculosis

Symptoms related to the specific disorder

A doctor's examination

Usually examination, culture, and other tests of a tissue sample to identify the microorganism

Mental disorders (such as depression or obsessive-compulsive disorder)

Withdrawal from usual activities

Sluggishness or sadness

Sometimes weight gain or weight loss and difficulty sleeping or too much sleep

A doctor's examination

Poor nutrition (as may result from poverty, eating disorders, or excessive dieting)

Often low body weight and body fat or a significant loss of weight over a short time

A doctor's examination


A stressful life event, difficulty concentrating, worry, and sleep problems (too much or too little)

A doctor's examination

* Drugs can also cause amenorrhea (see Table below).

† Features include symptoms and results of the doctor's examination. Features mentioned are typical but not always present.

‡ High levels of prolactin (a hormone that stimulates the breasts to produce milk) can result in no periods.

CT = computed tomography; MRI = magnetic resonance imaging.

Drugs That Can Cause Menstrual Periods to Stop




Drugs that can increase the production of prolactin*

Antihypertensive drugs




Production of breast milk in women who are not breastfeeding

Antipsychotic drugs







Illegal or recreational drugs




Drugs used to treat digestive disorders






Tricyclic antidepressants



Drugs that affect the balance of female and male hormones

Synthetic androgens


Development of masculine characteristics (such as excess body hair, a deepened voice, and increased muscle size)

Antidepressants (infrequently)




Irregular bleeding

* Prolactin is a hormone that stimulates the breasts to produce milk.


In girls or women of childbearing age, the first test is

  • A pregnancy test

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 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. Whether additional tests are needed and which tests are done depend on results of the previous tests. Typical tests include

  • Blood tests to measure levels of prolactin (to check for conditions that cause high levels), thyroid hormones (to check for thyroid disorders), follicle-stimulating hormone (to check for pituitary or hypothalamus malfunction), and male hormones (to check for disorders that cause masculine characteristics to develop)
  • Imaging tests of the abdomen and pelvis using computed tomography (CT), MRI, or ultrasonography to look for a tumor in the ovaries or adrenal glands
  • Examination of chromosomes in a sample of tissue (such as blood) to check for genetic disorders
  • Viewing of the uterus and usually fallopian tubes (hysteroscopy or hysterosalpingography) or imaging tests to check for blockages in these organs
  • Use of hormones (estrogen and a progestin or progesterone) to try and trigger menstrual bleeding

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.

If 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.

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.


When amenorrhea results from another disorder, that disorder is treated if possible. With such treatment, menstrual periods sometimes resume. For example, if an abnormality is blocking the flow of menstrual blood, it is usually surgically repaired, and periods resume. Some disorders, such as Turner syndrome and other genetic disorders, 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 germ cell cancer starts in the cells that produce eggs (germ cells) in the ovaries.

If a girl's periods never started and all test results are normal, she is examined every 3 to 6 months to check on the progression of puberty. She may be given a 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

  • Taking hormones to trigger release of an egg (ovulation) if pregnancy is desired
  • Treating symptoms and long-term effects of an estrogen deficiency (for example, by taking vitamin D, consuming more calcium in the diet or in supplements, or taking drugs, including hormone therapy and drugs that prevent bone loss such as bisphosphonates or denosumab for fractures caused by osteoporosis)
  • Reducing excess body hair

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 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.

Drugs Mentioned In This Article

Generic Name Select Brand Names
Metoclopramide REGLAN
progesterone CRINONE
Clomipramine ANAFRANIL
Haloperidol HALDOL
Desipramine NORPRAMIN
Risperidone RISPERDAL
Sertraline ZOLOFT
Methyldopa No brand name
Selegiline ELDEPRYL
Cimetidine TAGAMET
Olanzapine ZYPREXA
Paroxetine PAXIL
Verapamil CALAN
denosumab PROLIA
Reserpine No US brand name
Pimozide ORAP

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