Endometriosis is a medical condition where the tissue lining the
uterus (the endometrium) migrates to other parts of the body. The
condition can lead to serious health complications including chronic
pain, taut, distended abdomen, abnormal menstruation, infertility,
damage to other internal organs and impairment of fertility
Endometriosis typically occurs on the surfaces of organs in the pelvic
and abdominal areas. Health care providers may call areas of
endometriosis by different names, such as implants, lesions, or
The word endometriosis comes from the word "endometrium" - "endo"
means "inside" and "metrium" means "mother".
Most endometriosis is found in the pelvic cavity:
- On or under the ovaries
- On the fallopian tubes
- Behind the uterus
- On the tissues that hold the uterus in place, such as ligaments
- On the bowels or bladder
In extremely rare cases, endometriosis areas can grow in the lungs or
other parts of the body.
Who gets endometriosis?
Endometriosis can affect any menstruating woman, from the time of her
first period to menopause, regardless of whether or not she has
children, her race or ethnicity, or her socio-economic status.
Endometriosis can sometimes persist after menopause; or hormones taken
for menopausal symptoms may cause the symptoms of endometriosis to
Current estimates place the number of women with endometriosis between
2 percent and 10 percent of women of reproductive age. But, it's
important to note that these are only estimates, and that such
statistics can vary widely.
About 30 percent to 40 percent of women with endometriosis are
infertile, making it one of the top three causes of female
infertility. Some women don?t find out that they have endometriosis
until they have trouble getting pregnant.
If you have endometriosis and want to get pregnant, your health care
provider may suggest that you have unprotected sex for six months to a
year before you have any treatment for the endometriosis.
The relationship between endometriosis and infertility is an active
area of research. Some studies suggest that the condition may change
the uterus so it does not accept an embryo. Other work explores
whether endometriosis changes the egg, or whether endometriosis gets
in the way of moving a fertilized egg to the uterus.
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The exact cause of endometriosis remains unknown. Right now, a number
of theories try to explain the disease.
Endometriosis may result from something called "retrograde menstrual
flow, in which some of the tissue that a woman sheds during her period
flows into her pelvis. While most women who get their periods have
some retrograde menstrual flow, not all of these women have
endometriosis. Researchers are trying to uncover what other factors
might cause the tissue to grow in some women, but not in others. Of
course since endometriosis does occur in rare cases in men and also
seems to not be cured by hysterectomies this seems like a very far
Another theory about the cause of endometriosis involves genes. This
disease could be inherited, or it could result from genetic errors,
making some women more likely than others to develop the condition. If
researchers can find a specific gene or genes related to endometriosis
in some women, genetic testing might allow health care providers to
detect endometriosis much earlier, or even prevent it from happening
Researchers are exploring other possible causes, as well. Estrogen, a
hormone involved in the female reproductive cycle, appears to promote
the growth of endometriosis. Therefore, some research is looking into
endometriosis as a disease of the endocrine system, the body's system
of glands, hormones, and other secretions. Or, it may be that a
woman's immune system does not remove the menstrual fluid in the
pelvic cavity properly, or the chemicals made by areas of
endometriosis may irritate or promote growth of more areas. So, other
researchers are studying the role of the immune system in either
stimulating, or reacting to endometriosis.
Other research focuses on determining whether environmental agents,
such as exposure to man-made chemicals, cause endometriosis.
Additional research is trying to understand what, if any, factors
influence the course of the disease. We just don?t have answers on the
Dr. Deborah Metzger have been working on the idea that edometriosis is
actually an allergetic reaction. They have found that their patients
appear to have a large number of allergies, including allergies to
their own hormones such as Progesterone, LH, Estrodil, and also to
Candida (yeast). So in patients who have allergies to hormones, the
standard treatment of taking estrogen or progesterone in the form of
"the pill" can actually cause the endometriosis to become worse,
depending on which particualar allergy they have and the pill they are
taking. By treating these allergies, sometimes combined with surgical
removal, they have found that this seems to provide relief.
Some theories exist that endometriosis might be an autoimmune disease.
Another important area of NICHD research is the search for
endometriosis markers. These markers are substances made by or in
response to endometriosis that health care providers can measure in
the blood or urine. If markers are found, health care providers could
diagnose endometriosis by testing a woman's blood or urine, which
might reduce the need for surgery.
One of the most common symptoms of endometriosis is pain, mostly in
the abdomen, lower back, and pelvic areas. The amount of pain a woman
feels is not linked to how much endometriosis she has. Some women have
no pain even though their endometriosis is extensive, meaning that the
affected areas are large, or that there is scarring. Some women, on
the other hand, have severe pain even though they have only a few
small areas of endometriosis.
General symptoms of endometriosis can include (but are not limited
- Extremely painful (or disabling) menstrual cramps; pain may get worse
- Chronic pelvic pain (includes lower back pain and pelvic pain)
- Pain during or after sex
- Intestinal pain
- Painful bowel movements or painful urination during menstrual periods
- Heavy menstrual periods
- Premenstrual spotting or bleeding between periods
In addition, women who are diagnosed with endometriosis may have
gastrointestinal symptoms that resemble a bowel disorder, as well as
Currently, health care providers use a number of tests for
endometriosis. Sometimes, they will use imaging tests to produce a
"picture" of the inside of the body, which allows them to locate
larger endometriosis areas, such as nodules or cysts. The two most
common imaging tests are ultrasound, a machine that uses sound waves
to make the picture, and magnetic resonance imaging (MRI), a machine
that uses magnets and radio waves to make the picture.
The only way to know for sure that you have the condition is by having
surgery. The most common type of surgery is called laparoscopy. In
this procedure, the surgeon inflates the abdomen slightly with a
harmless gas. After making a small cut in the abdomen, the surgeon
uses a small viewing instrument with a light, called a laparoscope, to
look at the reproductive organs, intestines, and other surfaces to see
if there is any endometriosis. He or she can make a diagnosis based on
the characteristic appearance of endometriosis. This diagnosis can
then be confirmed by doing a biopsy, which involves taking a small
tissue sample and studying it under a microscope.
Your health care provider will only do a laparoscopy after learning
your full medical history and giving you a complete physical and
pelvic exam. This information, in addition to the results of an
ultrasound or MRI, will help you and your health care provider make
more informed decisions about treatment.
Cause of pain
How endometriosis causes pain is the topic of much research. Because
many women with endometriosis feel pain during or related to their
periods, some researchers are focusing on the menstrual cycle in their
search for answers about pain.
Normally, if a woman is not pregnant, her endometrial tissue builds up
inside her uterus, breaks down into blood and tissue, and is shed as
her menstrual flow or period. This cycle of growth and shedding
happens every month or so.
The endometriosis areas growing outside the uterus also go through a
similar cycle; they grow, break down into blood and tissue, and are
shed once a month. But, because this tissue isn't where it's supposed
to be, it can't leave the body the way a woman's period normally does.
As part of this process, endometriosis areas make chemicals that may
irritate the nearby tissue, as well as some other chemicals that are
known to cause pain.
Over time, in the process of going through this monthly cycle,
endometriosis areas can grow and become nodules or bumps on the
surface of pelvic organs, or become cysts (fluid-filled sacs) in the
ovaries. Sometimes the chemicals produced by the endometriosis can
cause the organs in the pelvic area to scar, and even to scar
together, so they appear as one large organ.
In more severe cases of endometriosis pain, while worse during the
menstrual flow, is unrelenting.
Currently, there is no cure for endometriosis. Even having a
hysterectomy or removing the ovaries does not guarantee that the
endometriosis areas and/or the symptoms of endometriosis will not come
There are a number of treatments for both pain and infertility related
The treatments for endometriosis pain include:
Pain medication: Works well if your pain or other symptoms are mild.
These medications range from over-the-counter remedies to strong
Hormone therapy: Is effective if your areas are small and/or you have
minimal pain. Hormones can come in pill form, by shot or injection, or
in a nasal spray. Common hormones used to treat endometriosis pain are
progesterone, birth control pills, danocrine, and gonadatropin-releasing
hormone (GnRH). But in some women this type of treatment causes severe
side effects and worsening of symptoms. Go to the next section, What
are the hormone treatments for endometriosis pain? for more
Surgical treatment: Is usually the best choice if your endometriosis
is extensive, or if you have more severe pain. Surgical treatments
range from minor to major surgical procedures.
Allergy treatment has recently shown great promise. Unfortunately this
area is not yet widely recognized as a viable treatment option. Though
at this point endometriosis is also not widely recognized by many
Because hormones cause endometriosis to go through a cycle similar to
the menstrual cycle, hormones can also be effective in treating the
symptoms of endometriosis. In fact, if a woman's symptoms do not
respond to hormone therapy, health care providers may go over their
diagnosis of endometriosis again, to make sure she really has the
Health care providers may suggest one of the following hormone
Oral contraceptives or birth control pills regulate the growth of the
tissue that lines the uterus and often decrease the amount of
menstrual flow. In general, the therapy contains two hormones,
estrogen and progestin.
It often works as long as you take the pills. Once you stop the
treatment, your ability to get pregnant returns, and your symptoms of
endometriosis may also return. Many women continue the treatment
Some women take birth control pills continuously, without using the
sugar pills that signal the body to go through menstruation. When
birth control pills are taken in this way, the menstrual period may
stop altogether, which can reduce pain or get rid of it entirely.
Some birth control pills contain only progestin, a progesterone-like
hormone. Women who can't take estrogen use these pills to reduce
Some women may not have pain for several years after stopping
You may have some mild side effects from these hormones, such as
weight gain, bleeding between periods, and bloating. Some women have
severe side effects including nausea, vomitting, severe bleeding all
month long, and severe cramping all month long. If you have severe
side effects, let your doctor know and do not let your doctor downplay
your side effects.
Progesterone and progestin improve symptoms by reducing a woman's
period or stopping it completely.
As a pill taken daily, these hormones will reduce menstrual flow
without causing the lining of the uterus to grow. As soon as you stop
taking the pill form, you can get pregnant and your symptoms may
As an injection taken every three months, these hormones will usually
stop menstrual flow. It may take a few months for your period to
return after you stop taking the injections. When your period returns,
so does your ability to get pregnant.
You may gain weight or feel depressed while taking these hormones.
You may have worsening symptoms over time while taking these hormones.
Danocrine stops the release of hormones that are involved in the
You will probably get your period only now and then while taking this
drug; or, you may not get it at all.
You should take steps to prevent pregnancy while you are on this
medication because danocrine can harm a baby growing in the uterus.
Because you should avoid taking other hormones, like birth control
pills, while on danocrine, health care providers recommend that you
use condoms, a diaphragm, or other "barrier? methods to prevent
Common side effects include oily skin, pimples or acne, weight gain,
muscle cramps, tiredness, smaller breasts, and breast tenderness.
You may also have headaches, dizziness, weakness, hot flashes, or a
deepening of your voice while on this treatment.
Gonadatropin-Releasing Hormone (GnRH) Agonists? block the production
of certain hormones to prevent menstruation, which slows or stops the
growth of endometriosis, sending the body into a "menopausal" state.
GnRH agonist is used daily in a nose spray, or as an injection given
once a month or every three months.
Most health care providers recommend that you stay on the GnRH agonist
for about six months. After that time, your body will come out of the
menopausal state. You?ll start having your period again and could get
After women stop taking GnRH agonists for six months, about 50 percent
have some return of their endometriosis symptoms.
These medications also have side effects, including hot flashes,
tiredness, problems sleeping, headaches, depression, bone loss, and
vaginal dryness. And bone loss is a side effect you will want to
consider carefully as this can cause many problems.
Current research is exploring the use of other hormones in treating
endometriosis and pain related to endometriosis. Some of these include
GnRH antagonists, selective progesterone receptor modifiers, and
selective estrogen receptor modulators, also known as SERMs. For more
information about these hormones, talk to your health care provider.
Some women also have less pain from endometriosis after pregnancy, but
the reason for this is unclear. Researchers are trying to determine
whether it is because the hormones released by the body during
pregnancy also lessen the growth of endometriosis, or if pregnancy
causes changes in the uterus or endometrium that lessen the growth of
endometriosis. Some women conversely have more pain during pregnancy
and a extreme worsening in symptoms. In any case, pain relief is no
reason to have a child. If you find a doctor recommends this solely to
help your symptoms you should look for another provider. If you do
plan on having children, sooner is better as endometriosis can lead to
If you have severe pain from endometriosis, your health care provider
may suggest surgery. At surgery, your health care provider can locate
any endometriosis and see the size and degree of growth; he or she may
also remove the endometriosis at that time.
You and your health care provider should talk about possible options
for removing endometriosis before your surgery. Then, based on the
findings and treatment at surgery, you and your health care provider
can discuss medical treatment options for after surgery.
Health care providers may suggest one of the following surgical
Laparoscopy is a way to diagnose and treat endometriosis without
making large cuts in the abdomen.
Laparoscopy involves a small cut in the abdomen, inflating the abdomen
with a harmless gas, and then passing a viewing instrument with a
light (called a laparoscope) into the abdomen. The surgeon uses the
laparoscope to see the growths.
To treat the endometriosis, the doctor can then remove the areas, a
process called excising (pronounced eks-size-ing), or destroy them
with intense heat and seal the blood vessels without stitches, a
process called cauterizing (pronounced kaw-terr-eyes-ing), or
vaporizing. The goal is to treat the endometriosis without harming the
healthy tissue around it.
If your surgeon is going to treat the endometriosis during your
laparoscopy, he or she must make at least two more cuts in your lower
abdomen, to pass lasers or other small surgical instruments into your
abdomen to remove or vaporize the tissue.
Doctors don't know the exact role of scar tissue in causing
endometriosis pain, but some will remove the scar tissue in case it is
causing the pain.
Usually, laparoscopy does not require an overnight stay in the
hospital. Recovery from laparoscopy is much faster than for major
surgery, like laparotomy, a procedure described below.
Major abdominal surgery, or laparotomy? is a more involved surgical
procedure, which requires longer recovery time (often one-to-two
During laparotomy, doctors either remove the endometriosis and/or
remove the uterus (a process called hysterectomy).
Doctors may also remove the ovaries and fallopian tubes at the time of
a hysterectomy, if the ovaries have endometriosis on them, or if
damage is severe. This process is called total hysterectomy and
Health care providers recommend major surgery as a last resort for
endometriosis treatment. Having the surgery does not guarantee that
the endometriosis will not return or that the pain will go away.
If a woman's pain is extreme, doctors may recommend more drastic
procedures that cut the nerves in the pelvis to lessen the pain. One
such procedure can be done during either laparoscopy or laparotomy.
Another procedure, called a laparoscopic uterine nerve ablation (LUNA)
is done during a laparoscopy. Because these procedures cannot be
reversed, you and your health care provider will need to talk about
these options in great detail before making the final decision about
In vitro fertilization (IVF) procedures are effective in improving
fertility in many women with endometriosis. IVF makes it possible to
combine sperm and eggs in a laboratory and then place the resulting
embryos into the woman's uterus. IVF is one type of assisted
reproductive technology that may be an option for women and families
affected by infertility related to endometriosis.
In the early stages of IVF, a woman takes hormones to cause "superovulation",
which triggers her body to produce many eggs at one time. Once mature,
the eggs are collected from the woman, using a probe inserted into the
vagina and guided by ultrasound. The collected eggs are placed in a
dish for fertilization with a man?s sperm. The fertilized cells are
then placed in an incubator, a machine that keeps them warm and allows
them to develop into embryos. After three-to-five days, the embryos
are transferred to the woman's uterus. It takes about two weeks to
know if the process is successful.
Even though the use of hormones in IVF is successful in treating
infertility related to endometriosis, other forms of hormone therapy
are not as successful. For instance, hormone therapy that prevents a
woman from getting her period, or from ovulating each month, does not
seem to improve infertility related to endometriosis. But, researchers
are still looking into hormone treatments for infertility due to
Laparoscopy to remove or vaporize the growths in women who have mild
or minimal endometriosis is also effective in improving fertility.
Some studies show that surgery can double the pregnancy rate. You can
review the What are the surgical treatments for endometriosis pain?
section of this publication for more information on laparoscopy.
Is endometriosis the same as endometrial cancer?
Endometriosis is not the same as endometrial cancer. Remember that the
word endometrium describes the tissue that lines the inside of the
uterus. Endometrial cancer is a type of cancer that affects the lining
of the inside of the uterus. Endometriosis itself is not a form of
Does endometriosis lead to cancer?
Current research does not prove an association between endometriosis
and endometrial, cervical, uterine, or ovarian cancers. In very rare
cases (less than 1 percent) endometriosis is seen with a certain type
of cancer, called endometrioid cancer; but, endometriosis is not known
to cause this cancer.
But, scientists still don't know what causes endometriosis or what its
mechanisms are in the body. In addition, many women are never
diagnosed as having endometriosis, which makes linking the condition
to other diseases more difficult.
For this reason, women who are diagnosed with endometriosis need to be
especially watchful of changes to or in their bodies; they need to
communicate these changes to their health care providers as soon as
possible, to ensure their own health.
In most cases, the symptoms of endometriosis lessen after menopause
because the growths gradually get smaller. For some women, however,
this is not the case.
The important thing to remember that only you know how bad your pain
is. If you find that your doctor does not take you seriously or
refuses to answer your questions, find another provider. Women that
successfully recover from endometriosis are usually working with their
doctors to find treatments that work for them, rather than "standard"
treatments. Everyone is individual and needs to have a treatment plan
that improves symptoms for them. And your doctor should not blame you
for your pain. It's a real disease despite our current lack of
understanding about it.