What is endometriosis?
endometrium is the tissue that lines the uterus.
During each menstrual cycle, a new endometrium grows, getting ready for a
possible pregnancy. If you don't become pregnant during that cycle, the
endometrium sheds, which you know as your
endometrium tissue that grows outside of the uterus, usually on the
fallopian tubes, the outer surface of the uterus, the
bowels, or other abdominal organs. In rare cases, it can affect other organs
and structures in the body.
Endometriosis growths are called
"implants." These implants grow, bleed, and break down with each menstrual
cycle, just like the endometrium does. This can cause pain and can make it
difficult to become pregnant (infertility). In some cases, scar
tissue forms around implants. Scar tissue can also cause pain and infertility
and can interfere with an organ's normal function.
How will endometriosis affect me?
usually a long-lasting (chronic) disease. While some women with endometriosis
never have symptoms or problems, others develop mild to severe symptoms or
infertility. Between 20% and 40% of women who are infertile have
endometriosis.2 In any given case, it is impossible
to know whether endometriosis will get worse, improve, or stay the same until
Endometriosis growths (implants) go through the same
growing, breaking down, and bleeding that the uterine lining (endometrium) goes
through with each menstrual cycle. This is why endometriosis pain often starts
as mild discomfort a few days before the menstrual period and why it usually
improves during the period. But if an endometriosis implant grows in a
sensitive area such as the rectum, it can eventually cause constant pain or
pain during certain activities such as sex, exercise, or bowel
Endometriosis symptoms often improve during pregnancy,
and they usually disappear after menopause. These are times when estrogen
levels are low, which slows or stops endometriosis growth.3 For most women, endometriosis symptoms also improve with
hormonal treatments that lower estrogen levels.
How does hormone therapy work?
reduces estrogen levels in your body. Because of this, you cannot use hormone
therapy if infertility is your main concern.
Birth control hormones (patch, pills, or ring) control the menstrual cycle. This stops
ovulation and endometrium growth and shrinks
endometriosis implants. For most women, this therapy is doesn't usually have
serious side effects, lowers ovarian cancer risk (which is higher with
endometriosis), and can be used long-term until menopause. For more general
information on birth control hormones, see
Birth control pill, patch, or ring.
Gonadotropin-releasing hormone agonist (GnRH-a) therapy (such as Lupron, Synarel, or Zoladex)
lowers estrogen to the levels women have after menopause. GnRH-a therapy is
limited to a short period of time (3 to 6 months) because it thins the bones,
which can lead to
osteoporosis. It is usually used with a little added
estrogen and progestin (add-back therapy) to prevent bone loss and menopause
side effects. Using GnRH-a therapy after surgery may relieve pain for a longer
time by preventing the growth of new or returning endometriosis.4
Progestin creates progestin levels in the body that
are similar to pregnancy. This stops monthly ovulation and lowers estrogen,
which shrinks endometriosis implants and reduces pain for most women. High-dose
progestin (such as the Depo-Provera shot) is not a long-term treatment-two or
more years of treatment may weaken your bones.5 Talk
to your doctor about whether the
progestin intrauterine device (Mirena) might offer you
progestin benefits with lower side effect risks.
Danazol therapy lowers estrogen levels and raises male
hormone (androgen) levels, which puts the body in a state
similar to menopause. This shrinks endometriosis implants and reduces pain for
most women. But danazol side effects are usually worse than GnRH-a side
effects, making danazol a last-choice therapy.
Aromatase inhibitors stop estrogen production. In small studies, aromatase
inhibitors have been shown to reduce pain and the chance of endometriosis
growths coming back. Aromatase inhibitors may help women with endometriosis who
have not had relief with hormonal treatments. Aromatase inhibitors are used in
combination with a hormonal treatment (such as birth control hormones or
progestin). Long-term use of aromatase inhibitors may cause bone loss. More
research needs to be done before it is known how well this treatment works and
what the side effects are.6
How well does hormone therapy work?
therapies are effective for 80% to 90% of women. While one may work for you, it
won't necessarily work for someone else. You may have to try one, then another,
before finding one that works for you. The major differences between hormone
therapy options are their side effects. Some, especially danazol, can cause
very unpleasant side effects. Others-such as GnRH-a or high-dose progestin-thin
the bones, so they cannot be used long-term.
If taking birth
control hormones works for you, you can use them for years (unless you plan a
pregnancy). Long-term use may prevent endometriosis from getting worse, lower
your ovarian cancer risk, and effectively prevent pregnancy. For some women in
their 40s, they also improve or prevent
perimenopausal symptoms that can make life difficult
as menopause approaches.
For some women, hormone therapy offers
only a temporary solution because pain relief lasts only a few months after
treatment. For others, relief is long-lasting.
Pain recurrence. After treatment with any hormone therapy,
endometriosis pain can, but does not always, return:2
year, up to 20% of all women treated will have pain that returns after hormone
- About 37% of women who use
hormone therapy for mild endometriosis have pain 5 years
- About 74% of women who use hormone
therapy for severe endometriosis have pain 5 years
What are the risks of taking these medicines?
Birth control hormones, GnRH-a, progestin, and danazol each have
different possible side effects and risks. The reduction of estrogen produces a
condition similar to menopause, with many of the same effects. Side effects can
include the following:
Birth control hormones.
Side effects do not affect every woman
and are generally mild. They often go away after the first few months of use.
They can include spotting between periods, nausea, headaches, breast
tenderness, mood changes, depression, less interest in sex, and lighter or
absent periods. Risks include an increased risk of
blood clots. Your health professional will not
prescribe birth control hormones if you have risk factors for blood clots, have
a history of breast cancer, or are older than 35 and smoke.
GnRH-a (such as Lupron, Synarel, or Zoladex).
Side effects can be reduced by taking a little estrogen with
or without progestin (add-back therapy) with GnRH-a therapy. Side effects are
like menopause and can include hot flashes, mood swings, vaginal dryness, less
interest in sex, insomnia, and headaches. Risks include
rapid loss in bone density of up to 1% per month, a decrease in "good"
cholesterol, and an increase in "bad" cholesterol. Add-back therapy prevents
some but not all bone loss (but it may make cholesterol changes worse). Bone
density improves after treatment, but it may not fully recover. This is why
GnRH-a therapy is limited to 3 to 6 months. No more than 2 rounds of therapy
are recommended, with time in between to recover bone loss. (After careful
discussion with your gynecologist.)
Side effects may include
mood changes and depression, bloating and weight gain, weight loss, breast
tenderness, and absent or light irregular periods. With high-dose progestin
(such as the Depo-Provera shot), risks include loss in
bone density after 2 years of use. Bone density is thought to rapidly improve
after treatment, but teens may not fully recover lost bone. Fertility can take
a year or more to return after high-dose progestin therapy.
Side effects are common with
this therapy and are caused by higher male hormone (androgen) levels. Side
effects include decreased breast size, muscle cramps, more facial and body
hair, depression, weight gain, acne, skin rash, and oily skin and hair along
with deepening of the voice, which can be permanent. Risks include an increase in "bad" cholesterol (more likely
than with GnRH-a); worsening of liver, heart, or kidney disease; and increased
ovarian cancer.7 No more
than 6 to 9 months of therapy is recommended.
include headache, nausea, diarrhea, and hot flashes. Risks include bone loss with long-term use. This treatment is
still being studied for use in endometriosis. More research needs to be done
before it is known how well this treatment works and what the side effects
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