With each menstrual cycle, the mucous membranes lining the womb (endometrium) cause the uterus to thicken. When endometrial cells are found outside of the womb, in the ovaries, cervix, vagina, fallopian tubes, the back and front of the uterus, the pelvis and back wall, intestines and bladder and ureter, endometriosis is diagnosed. Affecting approximately 10 percent of women, endometriosis can cause infertility and pelvic pain, especially during menstrual cycles and sexual intercourse.


Symptoms for endometriosis may occur at any time during the menstrual cycle. Some women experience mild endometriosis with little or no pain. Pelvic pain that extends down to the legs during the menstrual cycle is common but some women experience a throbbing, gnawing and dragging pain and describe a feeling that their “insides” are being pulled down. This pain can range from mild to severe, sometimes so severe it can be disabling.  

Other symptoms include:

  • Pain during sexual intercourse.
  • Urinary urgency and pain while voiding.
  • Lower back or abdominal pain.
  • Chronic tiredness.
  • Constipation.
  • Shooting rectal pain and pain during a bowel movement, usually due to bowel endometriosis.
  • Pain during ovulation.
  • Inflammation of the pelvic cavity.
  • Pain while standing or walking.
  • Pain from adhesions (scar tissue) that bind the fallopian tubes, ovaries, uterus, bowels and bladder in ways that are painful to women all the time.


Causes and Risk Factors

When a woman goes through her menstrual cycle, shedding the endometrial tissue due to hormonal changes in her body, the endometrial tissue found outside the uterus is also responding to the hormones. Since this tissue cannot be expelled through the vagina, it remains inside the body and may stay there, unnoticed, for many years.

Although the exact reason endometrial tissue is able to grow outside of the womb is unknown, there are theories:

  • Retrograde menstruation, when menstrual debris goes backwards out of the fallopian tubes during a period.
  • Most women have some degree of retrograde menstruation though their immune system is able to clear the debris and prevent the development of endometriosis.  The immune system typically prevents tissue from growing where it doesn’t belong.
  • Hormonal changes during ovulation and menstruation.
  • In severe cases, masses, lesions and scar tissue may form in the endometrium.

Women with severe endometriosis may have problems with fertility due in part to anatomical distortions and adhesions, similar to what a person would have following an injury.

Having a first-degree relative with endometriosis may increase a woman’s chance of developing the condition.


Your doctor may feel endometrial growths during a pelvic exam and order imaging tests to identify endometrial cysts or larger areas of endometriosis. Your doctor may initially ask for an ultrasound or an magnetic resonance imaging (MRI) to get a view of the inside your uterus.

The most definitive test to determine the existence and severity of endometriosis is laparoscopy, a minimally invasive surgical procedure where a scope with a small camera is inserted through a small incision near the belly-button. A biopsy may be taken at this time to rule out other illnesses. The stage of endometriosis often guides the treatment:

Stage I - Minimal evidence of endometriosis with only superficial lesions.

Stage II - Mild evidence as above, with some deep lesions.

Stage III - Moderate evidence as above, plus a presence of endometriomas (a pelvic mass) and adhesions in the ovary.

Stage IV - Severe evidence with all of the above and large endometriomas and adhesions.


The doctors at Minimally Invasive Gynecologic Surgery Center at Cedars-Sinai are experts at treating endometriosis with an emphasis on preserving fertility.

A big challenge for women with endometriosis is getting pregnant. For some, surgery can improve the chance of natural conception. For others, infertility therapies, such as ovulation induction or in vitro fertilization, may be more effective.

Hormonal preparations are available to treat endometriosis, although there may be some adverse effects with long-term hormone use. Typically, symptoms return when the hormone therapy is stopped and is not recommended for women who want to become pregnant.

Surgery to remove the endometrial tissue remains an option although the tissue may regrow in a few years. Using minimally invasive surgical techniques, fertility may be preserved, enabling you to become pregnant. Surgical options include:

  • A conservative approach that removes lesions and adhesions but retains reproductive organs.
  • A semi-conservative approach which allows ovarian function to continue, avoiding the symptoms of menopause.

For women who do not want to become pregnant, a total hysterectomy including removal of the ovaries, typically through minimally invasive surgery techniques, may be the only option to bring total relief. The cessation of hormone activity will cause menopause-like symptoms, including hot flashes.

Conservative therapies such as anti-inflammatory drugs, yoga, acupuncture and relaxation techniques might provide some benefit.

Although no cure currently exists for endometriosis, medications and surgery can help lessen its severity. At Cedars-Sinai, our physicians are working on a number of research studies to improve standard therapies and discover new ones, including a cure. Your doctor will discuss treatment options with you.