What is endometriosis and how is it different from primary dysmenorrhea?

Endometriosis. Endometriosis is a bening disease defined by the presence of endometrial glands ( lining of inside the uterus) outside the uterus and its associated with pelvic pain and infertility. The disease tends to progress and recurrs. Primary dysmenorrhea is when no specific diagnosis has been made and secondary dysmenorrhea is when an actual medical condition has been diagnosed.