Endometriosis is a condition in which cells that look and act like the cells that line the uterus (endometrial cells) are found in other locations in the body. These cells can attach to the ovaries, fallopian tubes, outer surface of the uterus, the bowels, other abdominal organs and, rarely, outside the abdomen. The places where the cells attach are called implants, or lesions.

Although the exact cause is unknown, retrograde menstruation (menstrual debris that goes backwards out of the fallopian tubes during periods) may play a part. Most women have some degree of retrograde menstruation; however, not all develop endometriosis. Altered immunity is also thought to play a role in developing endometriosis. Cedars-Sinai is actively evaluating these issues, as well as the roles of diet and environment in endometriosis.

Endometrial cells that are found outside the uterus respond to hormones released during the menstrual cycle in the same way as endometrial cells that are located in the uterus. At the beginning of the normal menstrual cycle, when the lining of the uterus is shed and menstrual bleeding begins, the sites of these abnormally located cells (implants) may swell and bleed.

The body responds to the swelling and bleeding by surrounding the cells with scar tissue. During the menstrual cycle, this scar tissue may become red, swollen and painful. As the scar tissue increases, it can form adhesions that cover and bind the abdominal organs. Adhesions can interfere with an organ's normal function.

Endometriosis is often progressive, meaning that the condition worsens over time. Some women experience no noticeable symptoms or none that they associate with a problem. For others, the symptoms may stay minor, go away or become severe gradually or suddenly. Possible symptoms include:

• Infertility
• Irregular ovulation and abnormal menstrual periods
• Pelvic pain

To help with the diagnosis of endometriosis, physicians at the center may use any combination of the following:

• Computed tomography (CT) scans
• Laparoscopy
• Magnetic resonance imaging (MRI) scans
• Medical history
• Pelvic exam
• Ultrasound

Although no cure currently exists for endometriosis, certain treatments can help lessen its severity, including:

• Drug therapy may be prescribed to shrink the endometrial implants, to control symptoms and to possibly reduce the spread of endometriosis, as well as birth control pills to correct irregular menstrual cycles.
• Electrocautery involves the use of laparoscopy (a minimally invasive procedure for seeing inside the body) and a laser beam or electric current to destroy endometrial implants and scarring.
• Hormone replacement therapy may help correct the hormone imbalance.
• Surgery may be necessary to remove or destroy endometrial implants or to remove the uterus and ovaries.