The colonisation of the uterine mucous membrane (endometrium) outside the uterus is known as endometriosis. Uterine mucous membrane "islands" form and can be found all over the abdomen, such as on the ovaries, the peritoneum, the bladder or between the vagina and the bowel. The symptoms of endometriosis often go unrecognised because they are interpreted by affected women as normal menstrual period symptoms. Endometriosis in the ovaries or in the fallopian tubes can cause infertility.

It is not completely clear how endometriosis occurs. It is suspected that some of the menstrual period blood flows into the abdomen via a fallopian tube during the period. This menstrual blood contains viable uterine mucous membrane cells which can colonise the abdomen. It is assumed that around 10 % of women suffer from endometriosis. The endometriosis nodes react to the female hormonal cycle in the same way as the uterine mucous membrane. This also results in a cycle-dependent build-up and reduction in the mucous membrane skin outside the uterus and accordingly to bleeding during the menstrual period.

The symptoms of endometriosis typically occur around the time of the menstrual period. Severe lower abdominal pain which already starts several days before menstruation can be an indication of endometriosis. However, endometriosis is often also connected with chronic lower abdominal pain or back pain. Some women report suffering pain during sexual intercourse. Endometriosis is often not viewed as a disease in its own right because the symptoms frequently occur in connection with the menstrual period.

Therefore, women should undergo a medical examination for severe menstruation symptoms or chronic lower abdominal or back pain. In this way, endometriosis can be recognised and treated in good time. It is also particularly important to recognise the disease as it more often than not a cause of infertility.

Various examinations are used to diagnose it. Sometimes endometriosis nodes can be felt between the bowel and the vagina in the gynaecological examination. Endometriosis nodes can be found in the abdomen with an ultrasound examination. Sometimes other examinations such as an MRI or even a laparoscopy are needed.

The treatment depends on where the endometriosis is located and how severe it is. As endometriosis nodes are hormone-related, hormone preparations can be used to treat them. If surgical removal is required, this can usually be done with a minimally invasive procedure. Find out more in the laparoscopy section. If the patient wishes to have children, this will have a bearing on the decision whether and how the surgical treatment will be carried out.