Endometriosis is a condition in which tissue that normally lines the inside of the uterus (the endometrium) spreads and implants in areas outside of the uterus. Often the site of the implantation is somewhere in the abdominal cavity. In patients with endometriosis, these implants of endometrium grow on a cyclic basis just as the normal endometrium does. When the normal endometrium sheds during your menstrual cycle causing your period, so do these endometrial implants. They can cause a small amount of bleeding within your abdominal cavity which results in pain.

Symptoms of endometriosis are often described as menstrual cramping and pain that begins before the onset of menstrual bleeding, and continues through the menstrual cycle. The severity of endometriosis often does not correlate with the degree of pain experienced with endometriosis. Often women with a small amount of endometriosis will have significant cyclic pain, and often women with a large amount of endometriosis will have minimal pain. Endometriosis is often seen in women who previously had pain-free menstrual cycles, and have gradually noticed a worsening in their pain.

The definitive diagnosis of endometriosis can only be made through surgery where the endometriotic lesions can be seen and sometimes biopsied to make the diagnosis.