Endometriosis is a puzzling disease affecting women in their reproductive years.
In endometriosis, tissue I like the endometrium is found outside the uterus, in other areas of the body. These growths can cause pain, infertility, and other problems. Endometrial growths have also been found outside the abdomen, in the lung, arm, thigh, and other locations, but these are uncommon. Like the lining of the uterus, endometrial growths usually respond to the hormones of the menstrual cycle. They build up tissue each month, break down, and cause bleeding.