Overview

What Is Endometriosis?

The tissue that lines the uterus is called the endometrium. Normally, if a woman doesn’t get pregnant, this tissue is shed each month during her period. In endometriosis, tissue that looks and acts like endometrial tissue implants outside the uterus. Each month, this misplaced tissue responds to the hormonal changes of the menstrual cycle. It builds up, breaks down and bleeds. But, the blood has nowhere to go. This causes surrounding tissue to become inflamed or swollen. It can also cause scar tissue, chronic pain and heavy periods.

With endometriosis, tissue inside the uterus begins to grow where it should not. This endometrial tissue can grow on the ovaries, the bowels or the walls of the pelvic cavity. In some cases, the tissue implants in the ovaries or fallopian tubes, which can cause infertility. Endometriosis is a main cause of infertility in women.