Home Page
Health Care Providers Section

E-mail this page   Printable View

Endometriosis: Overview and Risk Factors

Endometriosis is a common condition in which implants of endometrial tissue appear outside of the uterine cavity, usually within the pelvis. It is a frequent cause of dysmenorrhea and pelvic pain, and it may cause infertility. The pathogenesis is unknown but is thought to be associated with retrograde menstruation, in which menstrual tissue flows through the fallopian tubes and into the pelvic and abdominal peritoneum. Other hypotheses suggest the condition may result from displacement of endometrial tissue through surgical processes (eg, cesarean section, episiotomy), transport of cells through blood or lymph to distant locations, and differentiation of peritoneal cells to become endometrial cells.

Endometriosis is largely dependent upon active menstruation. The disease rarely occurs prior to menarche or after menopause. The most commonly involved locations are the peritoneal surface of the ovaries, anterior and posterior cul–de–sac, and the pelvic ligaments. In the gastrointestinal tract, the sigmoid colon and the appendix are most commonly affected. In some cases, the vagina and urinary system can be involved.

The severity of the condition varies greatly. It can be asymptomatic or severe and even debilitating. Symptoms are often nonspecific and do not always correlate with the severity of disease. Common symptoms include pelvic, abdominal, or low–back pain occurring in the premenstrual or perimenstrual period; abnormal uterine bleeding; dyspareunia; and infertility. Further symptoms occur based on the location of ectopic endometrial tissue (eg, rectal bleeding or pain with defection if colonic lesions are present, suprapubic pain upon urination if bladder lesions are present). Most women with endometriosis have no symptoms, and many women with severe pain have minimal visible endometriosis, suggesting that the body’s response to the implants is more important than the presence of the implants themselves.

Risk Factors

The risk factors for endometriosis are not well understood. It is most commonly diagnosed in women in their late 20s and early 30s, and the occurrence is increased by 7% in first–degree relatives. Dietary factors may play a role and are discussed in Nutritional Considerations below.


Endometriosis: Diagnosis >>