A condition in which endometrial tissue, which normally lines the uterus, is attached to other organs in the abdomen

  • Most common between the ages of 30 and 45
  • Sometimes runs in families
  • Not having had children is a risk factor

The lining of the uterus, known as the endometrium, is normally shed once a month during menstruation and then regrows. In endometriosis, some pieces of the lining are attached to organs in the pelvic cavity, such as the ovaries and the lower intestine. These pieces of endometrial tissue react to the hormones of the menstrual cycle and bleed during menstruation. The blood cannot leave the body through the vagina and this can cause irritation of the surrounding tissues, leading to pain in the abdomen and eventually scarring. Irritation of the ovaries may lead to blood-filled cysts.

Endometriosis is a common condition, affecting as many as 1 in 5 women of childbearing age. Women who do not have children until they are in their 30s and those who remain childless are more likely to develop the condition. Severe endometriosis can often cause problems with fertility (see Female infertility).

The exact cause of endometriosis is not known, but there are many theories. One theory is that fragments of endometrium shed during menstruation do not leave the body in the usual way through the vagina. Instead, they travel along the fallopian tubes, from where they may pass into the pelvic cavity and become attached to the surfaces of nearby organs.

What are the symptoms?

Endometriosis may not produce symptoms. If symptoms do develop, their severity varies from woman to woman. Symptoms may also vary depending on which organs are affected by the condition. They may include:

  • Pain in the lower abdomen, which often becomes more severe just before and during menstrual periods (see Dysmenorrhoea).

  • Heavier menstrual bleeding.

  • Pain during sexual intercourse.

If the endometrium grows on the lower intestine, you may develop diarrhoea or constipation, pain during bowel movements, and, in rare cases, bleeding from the rectum during menstruation.

What might be done?

In women who do not have symptoms, endometriosis may only be suspected following investigations for infertility. To help make a diagnosis, your doctor may carry out a pelvic examination. The diagnosis may be confirmed by ultrasound scanning. If ultrasound is inconclusive, laparoscopy may also be carried out.

There are many different treatments for endometriosis, and the one chosen depends on your age, which organs are affected, the severity of symptoms, and whether you wish to have children in the future. You may be offered hormonal or surgical treatment. In mild cases, treatment may not be necessary.

If your symptoms are troublesome, your doctor may prescribe one of several different hormonal treatments that stop menstruation for several months. These drugs may include the synthetic hormone gonadorelin (see Sex hormones and related drugs), which suppresses production of the female sex hormone oestrogen and has the effect of stopping menstruation. Alternatively, you may be given the combined oral contraceptive pill or progesterone-only medication for approximately 6 months, during which time the endometriosis should improve. If the condition does recur, it may be milder than before. Small fragments of endometrial tissue that do not respond to a period of hormonal treatment may be destroyed during a laparoscopy. However, endometriosis sometimes recurs after this treatment, and further operations may be necessary.

If you have severe endometriosis and you do not plan to have children, your doctor may suggest that you have a hysterectomy to remove the uterus. Both ovaries will also be removed, together with other areas that are affected by endometriosis. If the ovaries are removed before you have reached the menopause naturally, you will develop menopausal symptoms. To alleviate these symptoms, your doctor may recommend hormone replacement therapy.

What is the prognosis?

Although treatment is usually successful, endometriosis may recur until the menopause occurs and menstrual cycles end. Endometriosis is unlikely to recur if the ovaries are removed.

Test and Treatment: Laparoscopy

Treatment: Female Sterilization

From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.

The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.

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