Condition Basics

What is endometriosis?

Endometriosis (say "en-doh-mee-tree-OH-sus") is a problem many women have during their childbearing years. It means that a type of tissue that lines your uterus is also growing outside your uterus. 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.

Endometriosis usually isn't dangerous. But it can cause pain and other problems.

What causes it?

Experts aren't sure what causes endometriosis. Maybe endometrial cells get into the belly because of heavy bleeding or problems with reproductive organs. Or these cells may not be killed by the immune system outside the uterus. Or the cells might be carried to other parts of the body by blood or lymph fluid.

What are the symptoms?

The most common symptoms are pain, bleeding, and trouble getting pregnant. You may have pain in your lower belly, rectum or vagina, or lower back. Some women have heavy periods, bleeding between periods, bleeding after sex, or blood in their urine or stool. Symptoms often are most severe before and during your menstrual period.

How is it diagnosed?

Your doctor will ask questions about your symptoms, periods, past health, and family medical history. You may also have a pelvic exam. This may include checking both your vagina and rectum. The only way to find out for sure if you have endometriosis is to have a surgery called laparoscopy.

How is endometriosis treated?

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 have surgery to remove the endometrial tissue and scar tissue. If you want to get pregnant, you may need surgery to remove the endometrial tissue.

Health Tools

Health Tools help you make wise health decisions or take action to improve your health.

Decision Points focus on key medical care decisions that are important to many health problems.


Experts don't know what causes endometriosis. But they do know that the female hormone estrogen makes the problem worse. Women have high levels of estrogen during their childbearing years. This is when women have endometriosis.

Here are some possible causes.

  • Your immune system may not get rid of endometrial cells outside of the uterus like it should.
  • Heavy bleeding or an abnormal structure of the uterus, cervix, or vagina may cause 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 cesarean delivery.
  • Cells in the belly and pelvis may change into endometrial cells.
  • Endometrial cells may have formed outside your uterus before you were born.
  • It may be passed down through families.

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.


Some women with endometriosis don't have symptoms. Other women have symptoms that range from mild to severe. Symptoms may include:

  • Pain. You may have:
    • 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.
  • Trouble getting pregnant (infertility). This may be the only sign that you have endometriosis.
  • Abnormal bleeding. This may 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.

What Happens

Your uterus is lined with tissue called endometrium. When you have endometriosis, clumps of this tissue (called implants) form outside your uterus. The implants can be painful. Sometimes they form scar tissue or fluid-filled sacs (cysts). Scar tissue may make it hard to get pregnant.

Learn more

When To Call

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 you have a significant, unexplained change in your bowel movements.
  • You are not able to become pregnant after trying for 12 months.

Check your symptoms

Exams and Tests

To find out if you have endometriosis, your doctor will ask questions about your symptoms, periods, past health, and family history. (It sometimes runs in families.) You may also have a pelvic exam. This may include checking both your vagina and rectum.

Your exam, symptoms, and risk factors may strongly suggest that you have endometriosis. In that case, your doctor may have you try a nonsteroidal anti-inflammatory drug (NSAID) or hormone therapy before you have other tests. If treatment improves your symptoms after a few months, then it's more likely that you have endometriosis.

But the only way to be sure that you have it 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's inside your belly.

Learn more


Treatment Overview

Treatment depends on how much pain you have and whether you want to get pregnant. Treatments include:

  • Over-the-counter pain medicines like ibuprofen (such as Advil or Motrin) or naproxen (such as Aleve). These can reduce bleeding and pain.
  • Birth control pills. 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 tissue growths. But it can cause side effects, and pain may come back after treatment ends. Hormone therapy will keep you from getting pregnant.
  • Laparoscopy to remove growths and scar tissue. This may reduce pain, and it may help you get pregnant.

As a last resort for severe pain, some women have their uterus and ovaries removed (hysterectomy and oophorectomy).

If you're close to menopause, you may consider treatment with medicines rather than surgery. Endometriosis usually stops causing problems when you stop having periods.

Learn more


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.

  • Relieve back pressure.

    Lie on your back and place a pillow under your knees. Or lie on your side and bring your knees up to your chest.

  • Use relaxation techniques and biofeedback.
  • Exercise regularly.

    Exercise improves blood flow, increases pain-relieving endorphins naturally made by your body, and reduces pain.

Explore more



Surgery to remove endometrial growths and scar tissue doesn't cure endometriosis. But it does offer short-term results for most women and long-term relief for a few. Surgery to remove the uterus and ovaries can cure endometriosis if growths are removed too.footnote 1

Surgery may be recommended when:

  • Treatment with hormone therapy has not controlled symptoms, and symptoms interfere with daily living.
  • Endometrial growths or scar tissue interferes with other organs in the belly.
  • Endometriosis causes infertility.

Surgery choices include:

  • Laparoscopy. This is the most common procedure for treating endometriosis. It is used to look for and possibly remove growths and scar tissue. It is usually done through small incisions.
  • Hysterectomy with oophorectomy. This surgery removes the uterus and ovaries. It's used only when you have no plans to get pregnant and have had little relief from other treatments. It can help with pain for the long term. It causes early menopause.

Learn more


Related Information



  1. American College of Obstetricians and Gynecologists (2010, reaffirmed 2016). Management of endometriosis. ACOG Practice Bulletin No. 114. Obstetrics and Gynecology, 116(1): 225-236 .


Current as of: July 17, 2020

Author: Healthwise Staff
Medical Review:
Kathleen Romito MD - Family Medicine
Adam Husney MD - Family Medicine
Kevin C. Kiley MD - Obstetrics and Gynecology