Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Endometriosis Health Center

Font Size

Endometriosis - Cause

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 camera.gif 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 the uterus when you were a fetus.
  • It may be passed down through families.

WebMD Medical Reference from Healthwise

Last Updated: March 12, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
Next Article:

Today on WebMD

Endometriosis Overview
mature woman with serious expression
Distracted woman
healthtool pregnancy calendar
pelivic pain slideshow
estrogen gene
uterus and inlay of fibroids
woman talking to doctor
Doctor discussing screening with patient
young woman with thoughtful expression
contraceptive pills
Teenage girl with heat pad on stomach

WebMD Special Sections