What causes endometriosis?

In endometriosis the tissue that normally lines the inside of the womb passes to and starts to grow on the outside.

This tissue can grow in virtually any part of the body but is commonly found on the inner wall of the abdomen and pelvis, the outside of the womb and its supporting ligaments, the ovaries, the fallopian tubes, and the intestines. Nobody knows for sure how many women are affected by this condition. The typical features of endometriosis are found in about 1 in 4 women operated on in hospital, although most do not have any problems from them.

What causes endometriosis?

Endometriosis is not a disease as such and nobody knows exactly how it starts. Some doctors believe the tissue that is shed from the lining of the womb during a period somehow finds its way through the fallopian tubes to the outside of the womb, from where it spreads to the tissues that are affected. The hormones that are produced by the ovaries during the menstrual cycle stimulate these tissues just as they do the lining of the womb, making them bleed. This bleeding into the inside of the abdomen and pelvis is responsible for the pain of the condition as well as formation of adhesions that can lead to infertility (difficulty with conceiving).

What does it cause?

Endometriosis may not cause any problems and may only be found by chance during an operation in hospital. Typically it causes pain that is notoriously most severe around the time of a period, sometimes leading to a total disruption of lifestyle. The pain often begins before the period starts, continues throughout the duration of bleeding, and may persist for a few days after the bleeding has stopped.

In addition to pain, endometriosis can cause inflammation of the womb, fallopian tubes and lining of the pelvis, leading to formation of adhesions. These adhesions may cause blockage of the fallopian tubes resulting in infertility. The condition can also lead to formation of cysts (endometriomas) in the ovaries and other parts of the body. These may cause pain that is present all the time because of pressure on other tissues and could very rarely burst, leading to severe pain and an acute emergency. Endometriosis can develop into a most severe form where the vagina, rectum, bladder and ureters may become involved. This severe form of endometriosis (called rectovaginal endometriosis) causes profound menstrual and pelvic pain symptoms and could result in complete disruption of normal routines and sex life.

How is it detected?

The presence of endometriosis is often suspected because of the nature of the pain that it causes. Some women may have spotting of blood for a few days before their periods actually start. Occasionally it may be possible to see an endometriotic deposit (nodule) at vaginal examination in women with rectovaginal disease. It is usually possible to see ovarian endometriotic cysts on an ultrasound scan. Endometriosis is confirmed by seeing the typical deposits in the tummy during an open or telescopic operation (laparoscopy).

What is the treatment?

Very mild cases may require no treatment at all. Strong painkillers will be required if pain is a problem. The oral contraceptive pill is useful in some women because it suppress ovulation and so reduces blood levels of the hormones that stimulate deposits of endometriosis. The pill usually needs to be used for prolonged periods and some women may find its side effects disturbing.

Other medicines that prevent the ovaries from producing hormones that stimulate the lining of the womb have proved to be very effective remedies. These are available as daily nasal puffs or monthly (sometimes three-monthly) injections, and can be used for periods up to eighteen months each time. They can potentially be used for longer periods in combination with other hormone preparations. Endometriosis can unfortunately return after these medicines are stopped.
Surgery is used to cut away or burn off deposits of endometriosis and this provides the only real chance of curing the condition. Surgery is also useful for dividing adhesions and unblocking the fallopian tubes to restore fertility. Surgery also provides the only treatment option for women with severe endometriosis of the rectovaginal septum.

In the absence of adhesions or blockage of the tubes (obvious things that compromise fertility) the treatment of endometriosis in women who are actively trying to conceive raises a dilemma. This is because most of the medicines that are used for treatment of endometriosis either prevent or are not appropriate for use during pregnancy.

The woman and doctor will normally decide on what to do depending on the severity of her condition and urgency of her desire for pregnancy. Pregnancy is known to offer some relief from the pains of endometriosis because it stops the bleeding into the abdomen and pelvis from the deposits. Some women thus choose to try for a pregnancy first before having treatment for the condition.

Please follow this link for further patient information about endometriosis: https://www.rcog.org.uk/en/patients/patient-leaflets/endometriosis/