What is endometriosis?
Endometriosis (say "en-doh-mee-tree-OH-sus") is a problem many women have during their child-bearing years. It means that a type of tissue that lines your uterus is also growing outside your uterus. This does not always cause symptoms. And it usually isn't dangerous. But it can cause pain and other problems.
The clumps of tissue that grow outside your uterus are called implants. They usually grow on the ovaries, the fallopian tubes, the outer wall of the uterus, the intestines, or other organs in the belly. In rare cases they spread to areas beyond the belly.
How does endometriosis cause problems?
Your uterus is lined with a type of tissue called endometrium (say "en-doh-MEE-tree-um"). Each month, your body releases hormones that cause the endometrium to thicken and get ready for an egg. If you get pregnant, the fertilized egg attaches to the endometrium and starts to grow. If you do not get pregnant, the endometrium breaks down, and your body sheds it as blood. This is your menstrual period.
When you have endometriosis, the implants of tissue outside your uterus act just like the tissue lining your uterus. During your menstrual cycle, they get thicker, then break down and bleed. But the implants are outside your uterus, so the blood cannot flow out of your body. The implants can get irritated and painful. Sometimes they form scar tissue or fluid-filled sacs (cysts). Scar tissue may make it hard to get pregnant.
What causes endometriosis?
Experts don't know what causes endometrial tissue to grow outside your uterus. But they do know that the female hormone estrogen makes the problem worse. Women have high levels of estrogen during their childbearing years. It is during these years—usually from their teens into their 40s—that women have endometriosis. Estrogen levels drop when menstrual periods stop (menopause). Symptoms usually go away then.
What are the symptoms?
The most common symptoms are:
- Pain. Where it hurts depends on where the implants are growing. You may have pain in your lower belly, your rectum or vagina, or your lower back. You may have pain only before and during your periods or all the time. Some women have more pain during sex, when they have a bowel movement, or when their ovaries release an egg (ovulation).
- Abnormal bleeding. Some women have heavy periods, spotting or bleeding between periods, bleeding after sex, or blood in their urine or stool.
- Trouble getting pregnant (infertility). This is the only symptom some women have.
Endometriosis varies from woman to woman. Some women don't know that they have it until they go to see a doctor because they can't get pregnant or have a procedure for another problem. Some have mild cramping that they think is normal for them. In other women, the pain and bleeding are so bad that they aren't able to work or go to school.
How is endometriosis diagnosed?
Many different problems can cause painful or heavy periods. To find out if you have endometriosis, your doctor will:
- Ask questions about your symptoms, your periods, your past health, and your family history. Endometriosis sometimes runs in families.
- Do a pelvic examination. This may include checking both your vagina and rectum.
If it seems like you have endometriosis, your doctor may suggest that you try medicine for a few months. If you get better using medicine, you probably have endometriosis.
The only way to be sure you have endometriosis is to have a type of surgery called laparoscopy (say "lap-uh-ROSS-kuh-pee"). During this surgery, the doctor puts a thin, lighted tube through a small cut in your belly. This lets the doctor see what is inside your belly. If the doctor finds implants, scar tissue, or cysts, he or she can remove them during the same surgery.
How is it treated?
There is no cure for endometriosis, but there are good treatments. You may need to try several treatments to find what works best for you. With any treatment, there is a chance that your symptoms could come back.
Treatment choices depend on whether you want to control pain or you want to get pregnant. For pain and bleeding, you can try medicines or surgery. If you want to get pregnant, you may need surgery to remove the implants.
Treatments for endometriosis include:
- Over-the-counter pain medicines like ibuprofen (such as Advil or Motrin) or naproxen (such as Aleve). These medicines are called anti-inflammatory drugs, or NSAIDs. They can reduce bleeding and pain.
- Birth control pills are often used to treat endometriosis. Most women can use them safely for years. But you cannot use them if you want to get pregnant.
- Hormone therapy. This stops your periods and shrinks implants. But it can cause side effects, and pain may come back after treatment ends. Like birth control pills, hormone therapy will keep you from getting pregnant.
- Laparoscopy to remove implants and scar tissue. This may reduce pain, and it may also help you get pregnant.
As a last resort for severe pain, some women have their uterus and ovaries removed (hysterectomy and oophorectomy). If you have your ovaries taken out, your estrogen level will drop and your symptoms will probably go away. But you may have symptoms of menopause, and you will not be able to get pregnant.
If you are getting close to menopause, you may want to try to manage your symptoms with medicines rather than surgery. Endometriosis usually stops causing problems when you stop having periods.
Frequently Asked Questions
Learning about endometriosis:
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The exact cause of endometriosis is not known. Possible causes include the following:
- Your immune system may not be getting rid of endometrial cells outside of the uterus like it should.
- Heavy bleeding or an abnormal structure of the uterus, cervix, or vagina causes too many endometrial cells to go up through the fallopian tubes and then into the belly. (This is called retrograde menstruation).
- Blood or lymph fluid may carry endometrial cells to other parts of the body. Or the cells may be moved during a surgery, such as an episiotomy or a caesarean delivery.
- Cells in the belly and pelvis may change into endometrial cells.
- Endometrial cells may have formed outside the uterus when you were a fetus.
- It may be passed down through families.
Some women with endometriosis don't have symptoms. Other women have symptoms that range from mild to severe. Symptoms may include:
- Pain, which can be:
- Pelvic pain.
- Severe menstrual cramps.
- Low backache 1 or 2 days before the start of the menstrual period (or earlier).
- Pain during sexual intercourse.
- Rectal pain.
- Pain during bowel movements.
- Infertility may be the only sign that you have endometriosis. Between 20% and 40% of women who are infertile have endometriosis.footnote 1
- Abnormal bleeding. This can include:
- Blood in the urine or stool.
- Some vaginal bleeding before the start of the menstrual period.
- Vaginal bleeding after sex.
Symptoms are often most severe just before and during your menstrual period. They get better as your period is ending. Some women, especially teens, have pain all the time.
Endometriosis is usually a long-lasting (chronic) disease. When you have endometriosis, the type of tissue that lines your uterus is also growing outside your uterus. The clumps of tissue (called implants) may have grown on your ovaries or fallopian tubes, the outer wall of the uterus, the intestines, or other organs in the belly. In rare cases they spread to areas beyond the belly.
With each menstrual cycle, the implants go through the same growing, breaking down, and bleeding that the uterine lining (endometrium) goes through. This is why endometriosis pain may start as mild discomfort a few days before the menstrual period and then usually is gone by the time the period ends. But if an implant grows in a sensitive area, it can cause constant pain or pain during certain activities, such as sex, exercise, or bowel movements.
Some women have no symptoms or problems. Others have mild to severe symptoms or infertility. There is no way to predict whether endometriosis will get worse, will improve, or will stay the same until menopause.
Between 20% and 40% of women who are infertile have endometriosis (some have more than one possible cause of infertility).footnote 1 Experts don't fully understand how endometriosis causes infertility. It could be that:footnote 2
- Scar tissue (adhesions) may form at the sites of implants and change the shape or function of the ovaries, fallopian tubes, or uterus.
- The endometrial implants may change the chemical and hormonal makeup in the fluid that surrounds the organs in the abdominal cavity (peritoneal fluid). This may change the menstrual cycle or prevent a pregnancy.
A common complication of endometriosis is the development of a cyst on an ovary. This blood-filled growth is called an ovarian endometrioma or an endometrial cyst. Endometriomas can be as small as 1 mm or more than 8 cm across. The symptoms of an ovarian cyst may be the same as those of endometriosis.
What Increases Your Risk
Your risk of endometriosis is higher if:
- You are between puberty and menopause (around age 50). After estrogen levels drop at menopause, your risk disappears.
- Your mother or sister has or had endometriosis. This makes it more likely you will have severe symptoms. This risk seems to be passed on by the mother.
- Your menstrual cycles are less than 28 days.
- Your menstrual flow is longer than 7 days.
- You started menstruation before age 12.
- You have never been pregnant.
- Your uterus, cervix, or vagina has an abnormal shape that blocks or slows menstrual flow.
When To Call a Doctor
Call a doctor immediately if you develop sudden, severe pelvic pain.
Call a doctor to schedule an appointment if:
- Your periods have changed from relatively pain-free to painful.
- Pain interferes with your daily activities.
- You begin to have pain during intercourse.
- You have painful urination, blood in your urine, or an inability to control the flow of urine.
- You have blood in your stool, you develop pain, or a you have a significant, unexplained change in your bowel movements.
- You are not able to become pregnant after trying for 12 months.
If you have mild pain during your period but have no other symptoms or concerns, you can wait through several menstrual cycles. Then at your next routine visit with your doctor, you can discuss your pain. Home treatment may be all that you need to relieve mild pain.
Who to see
If your case is complicated or your main problem is infertility, you may be referred to:
To prepare for your appointment, see the topic Making the Most of Your Appointment.
Examinations and Tests
To see whether your symptoms are caused by endometriosis, your doctor first will:
- Talk to you about your family and medical history, symptoms, and menstrual periods.
- Do a pelvic examination. This often includes checking both the vagina and rectum.
If your examination, symptoms, and risk factors strongly suggest that you have endometriosis, your doctor may suggest that you first try a non-steroidal anti-inflammatory drug (NSAID) and/or hormone therapy before you have other tests. If treatment improves your symptoms after a few months, the diagnosis of endometriosis is more certain.
Laparoscopy is a surgical procedure used to diagnose and treat endometriosis. If your doctor recommends a laparoscopy, it will be used to look for and possibly remove implants and scar tissue. But laparoscopy is not always needed. It is usually done when infertility requires rapid treatment and probable surgery or when treatment has not relieved pain or infertility.
Tests for ovarian cysts or other problems
If your doctor feels an abnormal mass during the pelvic examination, you may have a cyst on the ovary (ovarian endometrioma) or another problem. You may need a transvaginal ultrasound, a CT scan, or an MRI.
There is no cure for endometriosis, but treatment can help with pain and infertility. Treatment depends on how severe your symptoms are and whether you want to get pregnant. If you have pain only, hormone therapy to lower your body's estrogen levels will shrink the implants and may reduce pain. If you want to become pregnant, having surgery, infertility treatment, or both may help.
Not all women with endometriosis have pain. And endometriosis doesn't always get worse over time. During pregnancy, it usually improves, as it does after menopause. If you have mild pain, have no plans for a future pregnancy, or are near menopause (around age 50), you may not feel a need for treatment. The decision is up to you.
If you have pain or bleeding but aren't planning to get pregnant soon, birth control hormones (patch, pills, or ring) or anti-inflammatories (NSAIDs) may be all that you need to control pain. Birth control hormones are likely to keep endometriosis from getting worse.footnote 4 If you have severe symptoms or if birth control hormones and NSAIDs don't work, you might try a stronger hormone therapy.
Besides medicine, you can try other things at home to help with the pain. For example, you can apply heat to your belly, or you can exercise regularly.
If hormone therapy doesn't work or if growths are affecting other organs, surgery is the next step. It removes endometrial growths and scar tissue. This can usually be done through one or more small incisions, using laparoscopy.
Laparoscopy can improve pain and your chance for pregnancy.
In severe cases, removing the uterus and ovaries (hysterectomy and oophorectomy) is an option. This surgery causes early menopause. It is only used when you have no pregnancy plans and have had little relief from other treatments.
Endometriosis cannot be prevented. This is in part because the cause is poorly understood. But long-term use of birth control hormones (patch, pills, or ring) may prevent endometriosis from becoming worse.
Home treatment may ease the pain of endometriosis. You can try the following things along with your other treatments.
- Apply heat to your lower belly. Use a heating pad or hot water bottle, or take a warm bath. Heat improves blood flow and may relieve pelvic pain.
- Lie down and place a pillow under your knees. When you lie on your side, bring your knees up to your chest to relieve back pressure.
- Use relaxation techniques and biofeedback.
- Exercise regularly. It improves blood flow, increases pain-relieving endorphins naturally made by the body, and reduces pain.
- Try sexual activity. This may (or may not) help with cramping and backaches.
Medicines can be used to reduce pain and bleeding and, in some cases, to shrink endometriosis growths. For women who are not trying to get pregnant, birth control hormones and anti-inflammatories (NSAIDs) are usually recommended first. They are least likely to cause serious side effects and can be a long-term treatment option.footnote 1 But if infertility from endometriosis is your main problem, medicines are generally not used.
- Anti-inflammatories (NSAIDs) reduce
inflammation, and bleeding from endometrial tissue.
Check with your doctor
before you use a non-prescription medicine for more than a few days.
- Start taking the recommended dose as soon as your discomfort begins or the day before your menstrual period is scheduled to start.
- Take the medicine in regularly scheduled doses. Taking the medicine only when your pain is severe is not as effective.
- If one type of NSAID doesn't relieve your pain, try another type. Or try acetaminophen, such as Tylenol.
Be safe with medicines. Read and follow all instructions on the label.
- Birth control hormones (patch, pills, or ring) stop monthly ovulation and the growth, shedding, and bleeding that makes endometriosis painful. Birth control hormones improve endometriosis pain for most women.footnote 4 And they are the hormone therapy that is least likely to cause bad side effects. For this reason, many women can use them for years. Other hormone therapies can only be used for several months to 2 years.
- Gonadotropin-releasing hormone agonist (GnRH-a) therapy lowers estrogen, triggering a state that is like menopause. This shrinks implants and reduces pain for most women.
- Progestin (pills or Depo-Provera shot) stops ovulation and lowers estrogen. For most women, it shrinks endometriosis growths and reduces pain. Some studies show that the levonorgestrel intrauterine device (IUD) decreases pain.footnote 5
- Danazol therapy lowers estrogen levels and raises androgen levels, triggering a menopause-like state. This shrinks growths and reduces pain for most women. This relief usually lasts for 6 to 12 months after treatment. But danazol side effects can be significant.
All hormone therapies for endometriosis can cause side effects and pose certain health risks. Some cause especially unpleasant side effects. Before starting a medicine or hormone therapy, review its possible side effects. If they sound less difficult than your endometriosis symptoms, discuss the therapy with your doctor.
What to think about
Ovarian cancer risk is higher in women who have endometriosis. Using birth control hormones for 5 or more years lowers this risk.footnote 6
Although surgery doesn't cure endometriosis, it does offer short-term results for most women and long-term relief for a few.
Surgery may be recommended when:
- Treatment with hormone therapy has not controlled symptoms, and symptoms interfere with daily living.
- Endometrial implants or scar tissue (adhesions) interferes with the functions of other organs in the belly.
- Endometriosis causes infertility.
- Laparoscopy is the most common procedure used to diagnose and treat endometriosis. If your doctor recommends a laparoscopy, it will be used to look for and possibly to remove or destroy implants and scar tissue.
- Hysterectomy with oophorectomy is for women who have no plans to get pregnant. It can help with pain for the long term. But after your ovaries are removed, the side effects of low estrogen levels can be severe. And when you start menopause early, your risk of future osteoporosis increases unless you take measures to protect your bones.
What to think about
Some studies suggest that using hormone therapy after surgery can make the pain-free period longer by preventing the growth of new or returning endometriosis.footnote 4
To help the stress and pain of endometriosis, you can consider other treatments. Researchers have not yet looked at these therapies for endometriosis. But these treatments have proven benefits for treating other conditions:
Other Places To Get Help
- Fritz MA, Speroff L (2011). Endometriosis. In Clinical Gynecologic Endocrinology and Infertility, 8th ed., pp. 1221–1248. Philadelphia: Lippincott Williams and Wilkins.
- Macer ML, Taylor HS (2014). Endometriosis. In EG Nabel et al., eds., Scientific American Medicine, section 20, chap. 10. Hamilton, ON: BC Decker. http://www.sciammedicine.com/sciammedicine/secured/htmlReader.action?bookId=ACP&partId=part17&chapId=1005&type=tab. Accessed October 1, 2014.
- D'Hooghe TM (2012). Endometriosis. In JS Berek, ed., Berek and Novak's Gynecology, 15th ed., pp. 505–556. Philadelphia: Lippincott Williams and Wilkins.
- Ferrrero S, et al. (2010). Endometriosis, search date December 2009. Online version of BMJ Clinical Evidence: http://www.clinicalevidence.com.
- American College of Obstetricians and Gynecologists (2010, reaffirmed 2016). Management of endometriosis. ACOG Practice Bulletin No. 114. Obstetrics and Gynecology, 116(1): 225–236.
- American College of Obstetricians and Gynecologists (2010, reaffirmed 2012). Noncontraceptive uses of hormonal contraceptives. ACOG Practice Bulletin No. 110. Obstetrics and Gynecology, 115(1): 206–218.
Other Works Consulted
- American Society for Reproductive Medicine (2008). Treatment of pelvic pain associated with endometriosis. Fertility and Sterility, 90(Suppl 3): S260–S269.
- American Society for Reproductive Medicine (2012). Endometriosis and infertility: A committee opinion. Fertility and Sterility, 98(3): 591–598.
- D'Hooghe TM (2012). Endometriosis. In JS Berek, ed., Berek and Novak's Gynecology, 15th ed., pp. 505–556. Philadelphia: Lippincott Williams and Wilkins.
- Gilliland GB (2014). Sexual health: Endometriosis. In J Gray, ed., Therapeutic Choices. Ottawa: Canadian Pharmacists Association. https://www.e-therapeutics.ca/tc.showChapter.action?documentId=c0075. Accessed July 28, 2014.
- Lobo RA (2012). Endometriosis: Etiology, pathology, diagnosis, management. In GM Lentz et al., eds., Comprehensive Gynecology, 6th ed., pp. 433–452. Philadelphia: Mosby.
Primary Medical Reviewer Sarah Marshall, MD - Family Medicine
Thomas M. Bailey, MD - Family Medicine
Martin J. Gabica, MD - Family Medicine
Kathleen Romito, MD - Family Medicine
Specialist Medical Reviewer Kirtly Jones, MD - Obstetrics and Gynecology
Kevin C. Kiley, MD - Obstetrics and Gynecology
Current as ofNovember 30, 2016
Current as of: November 30, 2016
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