The endometrium is the tissue that lines the inside of the womb (uterus). Endometriosis is a condition where endometrial tissue is found outside the uterus. It is "trapped" in the pelvic area and lower tummy and sometimes in other areas of the body.

The exact number of women who develop endometriosis is not known. Many women have endometriosis without symptoms, or with mild symptoms, and are never diagnosed. Investigations to diagnose endometriosis are only done if symptoms become troublesome and are not eased by initial treatments.

If symptoms develop they typically begin between the ages of 25-40. Endometriosis can affect any woman, however:

• Endometriosis is rare in women past the menopause, as to develop endometriosis you need oestrogen, the female hormone. Oestrogen levels fall after the menopause.
• The combined oral contraceptive pill reduces the risk of developing endometriosis. This protective effect may persist for up to a year after stopping "the pill".

SYMPTOMS

Patches of endometriosis can vary in size from the size of a pinhead to large clumps. Many women with endometriosis have no symptoms. If symptoms develop, they can vary from person to person.

In general, the bigger the patches of endometriosis, the worse the symptoms. However, this is not always the case. Some women have large patches of endometriosis with no symptoms. Some women have just a few spots of endometriosis but have bad symptoms.

The main symptoms of endometriosis are:

• Pain in your lower tummy or back – usually worse during your period
• Period pain that stops you doing your normal activities
• Pain during or after sex
• Pain when passing urine or faeces during your period
• Feeling sick, constipation, diarrhoea, or blood in your urine during your period
• Difficulty getting pregnant
• Bleeding between periods
• Heavy periods

For some women, endometriosis can lead to feelings of depression.

CAUSES

Currently it is not known what causes endometriosis. There are many responsible factors, possibly including genetic, immunological and hormonal reasons.

Several theories have been suggested, including:

• Genetics – the condition tends to run in families and affects people of certain ethnic groups more than others
• Retrograde menstruation – when some of the womb lining flows up through the fallopian tubes and embeds itself on the organs of the pelvis, instead of leaving the body as a period
• A weak immune system
• Endometrium cells spreading through the body in the bloodstream or lymphatic system
• Patches of endometriosis tend to be "sticky" and may join organs to each other. For example, the bladder or bowel may "stick" to the uterus. Large patches of endometriosis may form into cysts which bleed each month when you have a period.

It is likely the condition is caused by a combination of different factors.

DIAGNOSIS & PROGRESSION

The symptoms caused by endometriosis can be caused by other conditions. Therefore, if any of the above symptoms become persistent then tests are usually advised to find the definite cause. 

See a GP if you have symptoms of endometriosis, especially if they're having a big impact on your life. It may help to write down your symptoms before seeing a doctor. A GP will ask about your symptoms and may ask to examine your tummy and vagina.

They may recommend treatments if they think you have endometriosis. If these do not help, they might refer you to a specialist called a gynaecologist for some further tests, such as an ultrasound scan or laparoscopy.

Endometriosis is usually confirmed by a laparoscopy. This is a small operation which involves making a small cut, under anaesthetic, in the abdominal wall below the tummy button. A thin telescope-like instrument (a laparoscope) is pushed through the skin to look inside. Patches of endometriosis can be seen by the doctor this way.

If endometriosis is left untreated, it becomes worse in about 4 in 10 cases. It gets better without treatment in about 3 in 10 cases. For the rest it stays about the same.

TREATMENT

There is currently no cure for endometriosis, but there are treatments that can help ease the symptoms. The main aims of treatment are to improve symptoms such as pain and heavy periods and to improve fertility if this is affected.

Treatment options include:

• Painkillers – such as ibuprofen and paracetamol
• Hormone medicines and contraceptives – including the combined pill, the contraceptive patch, progestogen hormone tablets, an intrauterine system (IUS), and medicines called gonadotrophin-releasing hormone (GnRH) analogues
• Surgery to cut away patches of endometriosis tissue
• An operation to remove part or all of the organs affected by endometriosis – such as surgery to remove the womb (hysterectomy)

Your doctor will discuss the options with you. Sometimes they may suggest not starting treatment immediately to see if your symptoms improve on their own.

If symptoms are mild and fertility is not an issue for you then you may not want any treatment. In about 3 in 10 cases, endometriosis clears and symptoms go without any treatment. You can always change your mind and opt for treatment if symptoms do not go or become worse.

Surgery

Some women with endometriosis have no symptoms and need no treatment. If symptoms are mild, painkillers alone may be fine. Hormone treatments usually work well to ease pain but do not improve fertility. Surgery may be needed if infertility is caused by endometriosis.

Sometimes an operation is advised to remove some of the larger patches of endometriosis. There are various techniques that can be used. Most commonly, a thin telescope-like instrument (a laparoscope) is pushed through a small cut in the tummy (abdomen).

If getting pregnant or fertility is not a concern for you and other treatments have not worked well, removal of the womb and ovaries may be an option. This has a high chance of success for curing the symptoms.

Symptoms often improve during pregnancy. Also, the longer you have endometriosis, the greater the chance of reduced fertility. You may need to take this into account if you have plans for having children. If your family is complete or you do not wish to get pregnant, your treatment options will be wider.

Length of treatment

It may take a few months of hormone treatment to get full benefit. Do persevere for a few menstrual cycles if pain does not ease straightaway. Progestogens, "the pill" and the LNG-IUS are suitable for long-term treatment.

Recurrences
Once the endometriosis has gone with treatment, it may come back again in the future. Further treatment may need to be considered if symptoms do come back.

COMPLICATIONS

Complications sometimes occur in women with severe, untreated endometriosis. For example, large patches of endometriosis can sometimes cause an obstruction of the bowel or of the tube from the kidney to the bladder.

One of the main complications of endometriosis is difficulty getting pregnant or not being able to get pregnant at all (infertility).

Surgery to remove endometriosis tissue can help improve your chances of getting pregnant, although there's no guarantee. Surgery for endometriosis can also sometimes cause further problems, such as infections, bleeding or damage to affected organs.

If surgery is recommended for you, talk to your surgeon about the possible risks.

SUPPORT

Endometriosis can be a difficult condition to deal with, both physically and emotionally.

As well as support from your doctor, you may find it helpful to contact a support group, such as the Endometriosis Association of Ireland and Endometriosis UK for information, advice and an online community for women affected by the condition.