The bleeding causes pain, especially during your period. The breakdown and bleeding will cause scar tissue, called adhesions. Adhesions will bind organs together and may cause even more pain. The cause of endometriosis in uncertain. It is most common in women in their 30s and 40s, but can occur at any age in a woman who menstruates.
Endometriosis is found most commonly in women who have never borne children.
Pain is a symptom of endometriosis. The amount of pain does not indicate how severe your condition is, however. Some women with endometriosis have no pain. Other symptoms may be spotting or infertility. Depending upon your symptoms you may be treated with medication, surgery or both.