Fast facts

  • In endometriosis, cells that normally line the uterus grow outside it, causing scarring and bleeding.
  • The main symptom of endometriosis is pain or cramping in the lower abdomen that usually occurs during a woman's period.
  • Endometriosis can cause some women to have difficulty getting pregnant.
  • While there is no cure for the condition, there are some medications and surgical treatments available that can help to relieve the symptoms.

What is endometriosis?

Endometriosis is a common condition that can affect women mainly during their child-bearing years. It occurs when cells that normally line the uterus grow outside the uterus. Endometrial cells can grow on the ovaries, the fallopian tubes and on the outer surface of the uterus, forming growths that can cause scar tissue and bleeding every month during a woman's menstrual cycle.

Fallopian tubes

The tube-like structures connecting a woman's uterus to her ovaries. Eggs released by the ovaries travel to the uterus via the fallopian tubes.


The tissue that lines a woman's uterus is called the endometrium. Normally, this tissue layer thickens once a month and is shed during a woman's period. This is known as the menstrual cycle.

Endometriosis occurs when cells from the endometrium grow in places outside the uterus, including the ovaries, fallopian tubes and outer surface of the uterus. Like the normal tissue lining the uterus, endometrium that grows outside the uterus also thickens and sheds once a month during a woman's period. However, because of the location of the endometrium, the blood and tissue cannot escape. This may result in blood blisters or scar tissue forming, which can irritate the surrounding tissue and organs.

sites of deposits associated with endometriosis, endometriosis presentation.Endometriosis. 

While it is not known exactly what causes endometriosis, some possible explanations for the condition include:

Retrograde menstruation

Retrograde menstruation, also known as backwards menstruation, occurs when blood and tissue shed during a woman's period flow backwards into the fallopian tubes and pelvic cavity, instead of out of the vagina. It is thought that during this process, endometrial cells stick to these structures, which can potentially lead to endometriosis.

Immune system disorder

It is thought that endometriosis can occur as a result of problems of the immune system. Normally your immune system will recognize and destroy any endometrial tissue growing in the wrong place. If your immune system is not working properly, then endometrial cells are able to grow outside of the uterus.

Fallopian tubes

The tube-like structures connecting a woman's uterus to her ovaries. Eggs released by the ovaries travel to the uterus via the fallopian tubes.

Pelvic cavity

The space within the pelvis, the bony structure in the lower part of the body trunk, which contains the bladder, reproductive organs in females, and the lower intestines.

Risk factors

Endometriosis is a condition that mainly affects women during their child-bearing years. However, endometriosis can also occur in women who have had menopause, a condition called postmenopausal endometriosis. Postmenopausal endometriosis can either be due to endometriosis that started during child-bearing years continuing through to the period after menopause, or in some women, endometriosis can develop in the postmenopausal period.

An important risk factor for endometriosis is having one or more relatives (mother, aunt or sister) with endometriosis.

Signs and symptoms

Some women with endometriosis may not experience any symptoms at all, or may experience one or more of the following:

  • Very painful periods;
  • Pain or cramping in the lower abdomen during and between periods;
  • Pain with bowel movements, or a feeling of being full;
  • Pain during sex, and;
  • Diarrhea, nausea or vomiting.

Methods for diagnosis

To work out if you have endometriosis, your doctor may ask you questions about your symptoms, give you a physical examination and conduct some diagnostic tests.

To rule out other conditions and look for signs of endometriosis, a doctor may perform an ultrasound scan, which uses sound waves to create an image of your body's internal organs. To be sure that your symptoms are caused by endometriosis, the doctor my also recommend a minor surgical procedure called a laparoscopy, which will enable them to see your pelvis and abdomen directly and look for endometrial growths. This involves the doctor inserting a thin tube with a camera on the end of it, called a laparoscope, into the abdomen through a small cut near the bellybutton.

Laparoscopic examination to diagnose endometriosis. 

Endometriosis can be classed as minimal, mild, moderate or severe based on the location, amount and size of the tissue growths that form. Minimal or mild endometriosis do not usually affect a woman's chances of getting pregnant. However, women with moderate or severe endometriosis may have difficulty getting pregnant.

Types of treatment

There is no known way to cure endometriosis, but there are medications that may help relieve some of the symptoms. Surgery to remove endometrial growths or remove part of the reproductive system may sometimes be required.


Pain relief

Over-the-counter pain-relief medication, such as aspirin, acetaminophen or non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, may help relieve the pain and cramping associated with endometriosis.

Hormonal treatment

Hormonal therapies are sometimes used to shrink endometrial growths and help relieve some of the associated symptoms. Some common hormone treatments that may be prescribed to treat endometriosis include:

  • Oral contraceptive pills;
  • Synthetic male hormones, such as danazol;
  • Progesterones, such as medroxyprogesterone acetate, and;
  • Gonadotropin-releasing hormone agonists, such as goserelin.


Laparoscopic surgery

Endometrial growths can be removed during laparoscopic surgery, also called keyhole surgery, which involves placing a thin tube with a camera on the end of it into the abdomen through a small cut near the bellybutton. During this procedure, a laser is used to remove growths. This procedure may reduce the symptoms of endometriosis and increase your chances of getting pregnant naturally. Unfortunately, the growths and symptoms may come back a few years after the surgery.


In severe cases, surgery to remove the uterus may be needed to treat the condition. This procedure is called a hysterectomy. It is usually only performed if other available treatments do not work, as it prevents women from being able to become pregnant in the future.


Having endometriosis may lead to trouble getting pregnant. Women with endometriosis also have a slightly higher chance of developing ovarian cancer and another type of cancer, called endometriosis-associated adenocarcinoma.

Endometriosis-associated adenocarcinoma

The abnormal growth of the uterine lining outside of the uterus.


The outlook for people with endometriosis depends on how severe it is and where the endometrial growths are located. The available medical and surgical treatments are usually effective at relieving pain in most women. In women with mild endometriosis, surgery to remove the endometrial growths can increase their chances of getting pregnant, while women with severe endometriosis who are having trouble conceiving may be able to become pregnant with in vitro fertilization (IVF) treatments.

In vitro fertilization

Fertilization of an egg with sperm outside a woman's body.


As it is not known exactly what causes endometriosis, there is no particular way to prevent it.

FAQ Frequently asked questions