Endometriosis is a condition in which endometrium, the tissue that normally lines the womb (uterus), grows outside the uterus. Endometriosis may cause fibrous scar tissue to form on the uterus. It can also affect the ovaries, fallopian tubes and the bowel. Endometriosis may cause very painful periods and reduce fertility or cause infertility. Medical or surgical treatment may help endometriosis.
Endometriosis is a condition in which the endometrium, the tissue that normally lines the womb (uterus), grows in locations outside the uterus. The endometrium normally responds to the sex hormones oestrogen and progesterone. In women with endometriosis, the misplaced endometrial cells in the pelvic cavity also respond to these hormones.
During ovulation, the endometrium and the misplaced endometrial cells thicken. Unlike the endometrium, the misplaced endometrial cells cannot leave the body via menstruation. They bleed, cause inflammation and pain and then heal. Over time, this process can create scar tissue.
Fibrous scar tissue can form on the uterus, causing the uterus to stick to the ovaries, fallopian tubes and bowel. Endometriosis may cause very painful periods and may reduce fertility, but there are a number of treatment options.
Symptoms of endometriosis
The pain of endometriosis can be so bad that it stops you from going to work or school. Usually, it causes pain around the time of your period, but for some women, the pain is almost constant. If you need treatment, you may need emotional as well as physical support.
The symptoms of endometriosis include:
- Painful periods
- Pain with sex
- Pelvic pain
- Ovulation pain
- Pain in the lower back and thighs
- Bowel symptoms
- Bladder symptoms
- Reduced fertility
- Nausea and lethargy
- Premenstrual syndrome (PMS).
Many women think that painful periods are normal. If you have bad period pain, you should see your doctor.
Causes of endometriosis
The causes of endometriosis remain unknown, but research suggests a number of possible causes and risk factors.
Endometriosis and retrograde menstruation
Retrograde menstruation is also known as ‘backward menstruation’. The lining of the uterus is mostly shed through the vagina during the period. But in many women, some of the menstrual fluid flows backwards into the fallopian tubes instead of leaving the body through the vagina.
Because the fallopian tubes are open-ended (they are not joined to the ovaries), menstrual fluid can drip into the pelvic cavity. It is suspected that, in women who experience endometriosis, the endometrial tissue contained in the menstrual fluid sticks to whatever structures it lands on (such as the ovaries) and the cells begin to grow.
Endometriosis and the immune system
Retrograde menstruation occurs in almost all women, but only three to 10 per cent of menstruating women develop endometriosis. One theory suggests that the immune systems of some women allow endometriosis to develop by failing to control or stop the growth of endometrial tissue outside the uterus.
Genetics and endometriosis
Research suggests that inheritance might play a role in the development of endometriosis. Women who have a first-degree relative (mother or sister) with endometriosis are more likely to have the condition.
Risk factors for endometriosis
Some of the suspected risk factors include:
- Menstrual cycle factors – including early onset of menstruation, heavy or painful periods, short menstrual cycles (less than 27 days) and long periods (more than one week)
- Allergies – such as food, eczema and hay fever
- Family history of endometriosis
- Exposure to toxins – some research suggests that persistent environmental pollutants, such as dioxins, might contribute to the development of endometriosis.
Reducing your risk of endometriosis
Factors that may help reduce your risk of endometriosis include:
- Aerobic exercise for five hours per week – studies show a 50 per cent reduction in the risk of recurrence
- Childbearing – for some women, this reduces the risk that endometriosis will recur
- The contraceptive pill – prevents ovulation and suppresses endometriosis.
Diagnosis of endometriosis
Diagnosis usually begins with a detailed medical history to help the doctor exclude other possible causes of your symptoms. Diagnosis of endometriosis can be difficult. The presence of typical symptoms of endometriosis and pain that does not improve with the usual medications for period pain can indicate the presence of the condition.
If necessary, further tests that can help diagnosis include:
- Blood test – might be useful in later stages of endometriosis
- Laparoscopy – surgical procedure performed under general anaesthetic, where a medical instrument with a video camera attached is used to examine your pelvic organs
- Ultrasound – a vaginal or abdominal instrument that uses sound waves to create a video image of your pelvic organs
- Colonoscopy – a medical instrument with a video camera attached that is used to examine your bowel. This is done if it is thought the endometriosis could also be affecting your bowel. You would be sedated for the procedure.
Endometriosis may not show up during an internal pelvic examination. Your doctor may need to refer you to a gynaecologist.
Treatment for endometriosis
Endometriosis can be treated with medications or with surgery. Sometimes both medication and surgery are used. Some women also benefit from natural therapies.
Observation with no medical intervention
In mild cases of endometriosis, it may be possible to simply monitor the condition with regular visits to your doctor or gynaecologist. Medications that inhibit prostaglandins (non-steroidal anti-inflammatory drugs such as ibuprofen and mefenamic acid) can help to control any associated pain.
If symptoms progress, talk over the medical options with your healthcare professional before making a final decision. Remember that a mild condition can become moderate to severe. Removal of scar tissue with surgery is the most effective treatment to lessen the chances of recurrence.
Hormone treatment for endometriosis
The misplaced endometrial cells are sensitive to hormones and respond to cyclical fluctuations of oestrogen and progesterone during the menstrual cycle. This causes bleeding and pain which hormone therapy can sometimes effectively manage.
Options for hormone therapy include:
- Progestins are a group of progesterone-like synthetic hormones that suppress the growth of misplaced endometrium. Side effects of gestrinone include weight gain, tender breasts, acne, depression, mood swings, fatigue, nausea and vomiting.
- Gonadotrophin-releasing hormone (GnRH) agonists (chemicals that trigger a response in cells) control the amount of oestrogen produced, and this inhibits the growth of the misplaced endometrial cells. Side effects of GnRH agonists include menopausal symptoms such as thinning of the bones, hot flushes, dry vagina, headaches, depression, loss of libido (sex drive) and night sweats. These side effects can be relieved with oestrogen and progesterone.
- The oral contraceptive pill is frequently used to achieve long-term suppression of endometriosis. It can be used to stop the disease progressing in women with mild disease or to stop the disease from recurring following surgical or hormonal treatment.
- Gestrinone is a synthetic hormone that supresses the misplaced endometrium. Side effects of gestrinone include weight gain, acne, depression, mood swings, hot flushes and loss of libido.
- Danazol is a mild form of the male hormone testosterone that reduces the amount of oestrogen produced by the ovaries to around the same level that occurs during menopause. Without oestrogen, the misplaced endometrial cells cannot grow. Danazol is now rarely used to treat endometriosis due to its serious side effects.
Make sure you are well informed about the possible side effects of these treatments before you and your doctor decide on your treatment.
Surgery for endometriosis
Surgical methods used to treat endometriosis include:
- Laparoscopic surgery (keyhole surgery) can be used to both diagnose and treat endometriosis. A slender tube is inserted into the abdominal cavity via a small incision and misplaced endometrium, cysts and adhesions are cut out (excision) or burnt (diathermy).
- Laparotomy is major surgery that is used to cut out or burn tissue or cysts when endometriosis is more severe.
- Bowel surgery may be necessary if the bowel has developed scarring from endometriosis.
- Hysterectomy (removal of the uterus) may be an option if endometriosis is significantly impacting your quality of life and other treatments have not worked. If your ovaries are removed during a hysterectomy, you will need to discuss hormone replacement with your doctor.
Combined treatment for endometriosis
In some cases, a woman will benefit from undergoing hormone therapy as well as surgery. Hormone therapy may be offered before or after the surgery, depending on the circumstances.
Endometriosis and complementary and alternative medicine
Some women find natural therapies to be helpful. It is important that you always tell your doctor about the kinds of complementary therapies you are using (or considering) as they may affect other treatments that you might be using.
Examples of different therapies include:
- Herbal medicine
- Traditional Chinese medicine
- Nutritional therapies
Where to get help
- Your doctor
- Your gynaecologist
- Endometriosis Care Centre of Australia Tel. (03) 9415 6855
Things to remember
- Endometriosis can cause painful adhesions on the uterus, ovaries, fallopian tubes and bowel.
- Painful periods are not always normal, so speak with your doctor if you have bad period pain.
- The exact cause is unknown, but research suggests that retrograde menstruation and family susceptibility might be involved.
- Treatment with medication or surgery might help the symptoms of endometriosis.
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This page has been produced in consultation with and approved by:
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Endometriosis Care Centre of Australia (ECCA)
Fact sheet currently being reviewed.
Last reviewed: February 2012
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