Absence of Menstrual Periods(Amenorrhea)
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.
Causes
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).
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
Testing
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.
Treatment
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.
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