Endometriosis

What is endometriosis?

The endometrium is the tissue that lines the inside of the uterus (womb). Endometriosis is a condition where endometrial tissue is found outside the uterus. It is 'trapped' in the pelvic area and lower abdomen.

About 1 in 10 women of childbearing age have some degree of endometriosis. Symptoms typically begin between the ages of 25-40. It can affect any woman. However:

• Sometimes it runs in families. Therefore, endometriosis is more common in close blood relatives of affected women.
• 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 oral contraceptive pill ('the pill') reduces the risk of developing endometriosis. This protective effect may persist for up to a year after stopping 'the pill'.

What causes endometriosis?

The exact cause is not known. It is thought that some cells from the lining of the uterus (the endometrium) get outside the uterus into the pelvic area. They probably get there by spilling backwards along the fallopian tubes when you have a period.

The endometrial cells continue to survive next to the uterus, ovary, bladder, bowel, or fallopian tube. The cells respond to the female hormone oestrogen, just like the lining of the uterus does each month. Throughout each month the cells multiply and swell, and then break down as if ready to be shed at the time of your period. However, because they are trapped inside the pelvic area, they cannot escape. They form patches of tissue called endometriosis.

Patches of endometriosis tend to be 'sticky' and may join organs to each other. The medical term for this is adhesions. 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. The cysts can fill with dark blood known as 'chocolate cysts'.

What are the symptoms of endometriosis?

Patches of endometriosis can vary in size from the size of a pinhead to large clumps. Symptoms vary, and include those listed below. 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.

• Painful periods. The pain typically begins a few days before the period and usually lasts the whole of the period. It is different to normal period pain which is usually not as severe, and doesn't last as long.
• Painful sex. The pain is typically felt deep inside, and may last for a few hours after sex.
• Pain in the lower abdomen and pelvic area. Sometimes the pain is constant, but is usually worse before and during a period.
• Other menstrual symptoms may occur. For example, bleeding in between periods.
• Difficulty becoming pregnant. This may be due to clumps of endometriosis blocking the passage of the egg from an ovary to the fallopian tube.
• Uncommon symptoms include pain on passing faeces (motions), pain in the lower abdomen when you pass urine, and blood in the urine or faeces. Very rarely, patches of endometriosis occur in other sites of the body. This can cause unusual pains in various parts of the body that occur at the same time as period pains.

The symptoms caused by endometriosis can be caused by other conditions. Therefore, tests are usually advised to find the cause of the symptoms. Endometriosis is usually confirmed by a laparoscopy. This involves making a small cut in the abdominal wall below the umbilicus (tummy button) under anaesthetic. A 'telescope' is pushed through the skin to look inside. Patches of endometriosis can be seen by the doctor.

How does endometriosis progress?

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. Endometriosis is not a cancerous condition. Complications sometimes occur in women with severe untreated endometriosis. For example, large patches of endometriosis can sometimes cause an obstruction (blockage) of the bowel or of the ureter (the tube from the kidney to the bladder).

What are the aims of treatment?

The main aims of treatment are to improve symptoms such as pain and heavy periods. Also, to improve fertility if this is affected. There are various treatment options which are discussed below.

Not treating as an option

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.

• Paracetamol taken during periods may be all that you need if symptoms are mild.
• Anti-inflammatory painkillers such as ibuprofen, diclofenac, naproxen, etc, may be better than paracetamol. However, some people have side-effects with anti-inflammatories.
• Codeine alone, or combined with paracetamol, is a more powerful painkiller. It may be an option if anti-inflammatories don't suit. Constipation is a common side-effect from codeine.

To ease pain during periods, it is best to take painkillers regularly throughout the time of your period rather than 'now and then'. You can take painkillers in addition to other treatments.

Hormone treatments for endometriosis

Understanding oestrogen and how hormone treatments work
Oestrogen is a hormone that is made in the ovaries. The cells that line the inside of the uterus (endometrial cells) need oestrogen to grow and survive. The endometrial cells outside the uterus that cause endometriosis also need oestrogen. Hormone treatment works by reducing the amount of oestrogen that you make, or by blocking the effect of oestrogen on the endometrial cells. The endometrial cells are then starved of oestrogen which they need to survive. Therefore, patches of endometriosis gradually shrink, and may clear away.

It may help to understand how oestrogen is made. Hormones called gonadotrophins are made in the pituitary gland, which is a gland next to the brain. Gonadotrophin hormones are released into the bloodstream and stimulate the ovaries to make oestrogen which is also released into the bloodstream. The stimulus to release gonadotrophins into the bloodstream comes from a hormone called gonadotrophin releasing hormone (or GnRH for short). This is made in the brain and travels to the pituitary. So, in effect there is a cascade:

The different hormone treatments work by affecting different parts of this cascade. However, the end result of all of them is to reduce the amount of oestrogen that is made, or to block the action of oestrogen on endometrial cells.

Types of hormone treatments
There are several options. They all have similar success rates at easing symptoms.

• The combined oral contraceptive pill ('the pill') is not strictly licensed for the treatment of endometriosis. However, many women report improved symptoms when they are on 'the pill'. The pill stops ovulation which reduces the amount of oestrogen made by the ovaries. Periods are lighter, less painful, and are predictable. Other symptoms such as painful sex, and pain in the pelvic area may also improve.
   
• Progestogen hormone tablets reduce the effect of oestrogen on the endometrial cells which causes the cells to 'shrink'. Progestogens also prevent ovulation which lowers the oestrogen level. Progestogen hormone tablets include norethisterone, dydrogesterone and medroxyprogesterone. Side-effects that may occur include: irregular menstrual bleeding, weight gain, mood changes, and bloating.
   
• Danazol works mainly by reducing the amount of gonadotrophins that you make. This has a 'knock-on' effect of reducing the amount of oestrogen that you make. Side-effects may occur including: weight gain, hair growth, acne, and mood changes. Rarely, it causes a deepening of the voice which may be irreversible. It usually stops periods too.
   
• Gestrinone is similar to danazol, but you only need to take it twice a week rather than daily.
   
• GnRH (gonadotrophin releasing hormone) analogues block the pituitary from releasing gonadotrophins. This greatly reduces the amount of oestrogen that you make in the ovaries. There are several GnRH analogue preparations which include buserelin, goserelin, nafarelin, leuprorelin, and triptorelin. Some preparations are taken as a nasal spray, some are given by injection. A six month course is usual. Side-effects may occur due to the very low levels of oestrogen that this treatment causes. For example, hot flushes, dry vagina, reduced sex drive, headaches, and difficulties with sleeping. Periods usually stop too. An option is to take a small dose of oestrogen and progestogen as hormone replacement therapy (HRT) to stop these side-effects. This 'add-back' HRT does not affect the effectiveness of the treatment.

You should use contraception with condoms if you have sex whilst taking hormone treatments (apart from 'the pill' which is a contraceptive). This is because there is a risk that hormone treatments may affect a developing baby.

Surgery for endometriosis

Sometimes an operation is advised to remove some of the larger patches of endometriosis. This may ease symptoms and increase the chance of pregnancy if infertility is a problem. If you have completed your family, and other treatments have not worked well, a hysterectomy (removal of the uterus) and removal of the ovaries may be an option. This has a high chance of success for curing the symptoms.

Some general points about the treatment of endometriosis

• Severity and type of symptoms may influence the choice of treatment. Some women with endometriosis have no symptoms, and no treatment may be needed. If symptoms are mild, painkillers alone may be sufficient. Hormone treatments usually work well to ease pain, but do not improve fertility. Surgery may be needed if infertility is caused by endometriosis.
   
• Success of treatment and side-effects. Overall, the hormone treatment options all have about the same success rate at easing pain. However, some women respond to one treatment better than others. Also, the treatments have different possible side-effects. You may try one treatment, and it may be fine. However, it is not unusual to switch from one treatment to another if the first does not suit.
   
• Age and plans for pregnancy. 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, and symptoms are severe, then hysterectomy (removal of the uterus) may be a good option.
   
• 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 straight away. Danazol, gestrinone, and GnRH analogues are usually only advised for six months. Symptoms may be much improved after six months treatment, but may recur once treatment is stopped. Progestogens or 'the pill' are suitable for long-term treatment.
   
• Combinations of treatment. Surgery to remove most of the endometrial patches followed by hormone treatment may be better at long-term easing of symptoms than just surgery alone.
   
• Recurrences. Once the endometriosis has gone with treatment it may recur again in the future. Further treatment may need to be considered if symptoms recur.

In summary

• Endometriosis can cause pain and may affect fertility.
• Treatment usually works well but symptoms may return once treatment is stopped.
• Hormone treatment usually eases pain, but does not improve fertility.
• Surgery usually improves pain and may also improve fertility.
• Endometriosis may recur, and a further course of treatment may then be needed.

Further help and information

© EMIS and PIP 2006   Updated: June 2006   PRODIGY Validated