Endometriosis is described as having four stages. Each stage is based on location, amount, depth, and size of lesions. The pain associated with endometriosis may not correlate with the stage of disease. For example, a women with Stage 1 endometriosis could have significant pain or very few symptoms.
Endometriosis lesions are most commonly found in the pelvic area on organs such as:
Some lesions can even form their own nerves—another reason there can be pelvic pain outside of the period. Over time, lesions can form scar tissue or adhesions between organs—meaning they stick together—which can cause even more pain.
Rarely, lesions can be found in areas further away from the pelvic area.