Pain is more than a physical stimulus from an anatomical
location
The theory that endometriosis has a multifactorial pathogenesis could
explain why endometriosis remains difficult to classify regarding
prognosis and clinical correlation. This multifactorial pathogenesis
includes endometriosis severity (stage, location, depth of invasion),
co-morbidity conditions, myofascial factors (muscle and fascial
involvement), and central sensitisation (17). According to the
International Association for the Study of Pain, the definition of pain
is “an unpleasant sensory and emotional experience associated with
actual or potential tissue damage”. Besides, it has become more clear
that pain experience is also influenced by psychological factors (e.g.
catastrophising, anxiety, coping) (18, 19) and central sensitisation
(persistent state of high reactivity) (20). This supports the theory
that not only the severity of the endometriosis is responsible for pain
symptoms. Endometriosis lesions on anatomical structures are not solely
responsible for the pain sensation: it seems far more complex than that.