However, unlike menstrual fluid from the uterus, which is discharged from the body during menstruation, blood from the misplaced tissue has no place to go, it is trapped. Tissues surrounding the area of endometriosis may become swollen or inflamed. The inflammation may produce scar tissue around the area of endometriosis. Physicians may use stages to describe the severity of endometriosis. Endometrial implants that are small and not widespread are considered minimal or mild endometriosis.
Moderate endometriosis means that larger implants or more extensive scar tissue is present.
Most often, the symptoms of endometriosis start years after menstrual periods begin. As time passes, those symptoms tend to gradually increase as the endometriosis areas increase in size. After menopause, the abnormal implants shrink away and much of the symptoms subside. Endometriosis is considered one of the three major causes of female infertility. However, unsuspected or mild endometriosis is a common finding among infertile women and how this type of endometriosis affects fertility is still not clear.