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Endometriosis
Definition:
Endometriosis is a condition in which the endometrium, tissue that normally lines the uterus, grows in other areas of the body, causing pain, irregular bleeding, and frequently infertility. The tissue growth typically occurs in the pelvic area, outside of the uterus, on the ovaries, bowel, rectum, bladder, and the delicate lining of the pelvis, but it can occur in other areas of the body as well. Text Continues Below
Causes, incidence, and risk factors:
The cause of endometriosis is unknown. However, a number of theories have been proposed. The retrograde-menstruation theory proposes that endometrial cells (loosened during menstruation) may "back up" through the fallopian tubes into the pelvis, where they implant and grow in the pelvic and/or abdominal cavities. The immune-system theory suggests that a deficiency in the immune system allows menstrual tissue to implant and grow in areas other than the uterine lining. Another theory suggests that the cells lining the abdominal cavity may spontaneously develop endometriosis. A genetic theory proposes that certain families may exhibit predisposing factors that lead to endometriosis. Once the endometrial cells implant in tissue outside of the uterus, they may become a problem. Each month the ovaries produce hormones that stimulate the cells of the uterine lining to multiply and prepare for a fertilized egg (swell and thicken). The endometrial cells outside of the uterus also respond to this signal, but they lack the ability to then separate themselves from the surrounding tissue and slough off during the next menstrual period. They sometimes bleed a little bit, but they heal and are stimulated again during the next cycle.
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