Endometriosis is a chronic but benign gynaecological problem that occurs in women of reproductive age. This is when tissue similar to the lining of the uterus (med. endometrium) grows on one or more organs. Endometriosis can affect not only the uterus, fallopian tubes and ovaries, but also the peritoneum, bowel and bladder, for example. The tissue growths or lesions designated as endometriosis sites grow and bleed, so that the tissue becomes inflamed and scarring ensues over time. These tissue changes make fertilisation or implantation of an embryo difficult.
The causes of endometriosis are not clear. There are different theories as to why tissue changes occur. These include:
Spread of endometrial cells in the abdominal organs due to return flow of the menstrual blood (retrograde menstruation)
Spread of endometrial cells via the blood and lymphatic vessels
Genetic factors that trigger a lesion
Malfunctions of the immune system
Environmental influences, in particular environmental contaminants such as PCB, DDT and dioxins, which interfere with the endocrine system
The complex symptoms and the development of endometriosis suggest that there is no single cause for its formation. It is much more likely that an interplay of different factors causes the disease.