Pathogenesis of Endometriosis: The Origin of Pain and Subfertility.

Endometriosis (EM) and adenomyosis (AM) are common conditions with pain and infertility as the principal symptoms. The pathophysiology of pain in EM and AM comprises sensory and somatoform pain mechanisms. Over time, these may aggravate and lead to individual complex disease patterns if not diagnosed and treated. Despite the known facts, several years often pass between the onset of symptoms and diagnosis. Chronic pain disorders with changes on a neuronal level frequently arise and are linked to depressive disorders, with the process becoming a vicious cycle. Additionally, women with EM and AM suffer from sub- and infertility. Low fecundity rates are caused by anatomical changes in combination with behavioral changes in the sexual activity of women with chronic pain as well as local proinflammatory factors that not only decrease implantation rates but also promote early abortions.