Endometriosis

Definition:

A condition in which the tissue that normally lines the uterus (endometrium) grows in other areas of the body, causing pain, irregular bleeding, and frequently, infertility. The tissue growth typically occurs in the pelvic area, on the ovaries, bowel, outside of the uterus, rectum, bladder, and the delicate lining of the pelvis, but it can occur in other areas of the body.

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. 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 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, however, they lack the ability to separate themselves from the 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. This ongoing process causes scarring and adhesions in the tubes and ovaries, and around the tubal fimbriae. These adhesions can make transfer of an ovum from the ovary to the fallopian tube difficult or impossible. They can also stop passage of an ovary down the fallopian tube to the uterus.

Once in a while the growing cells will penetrate the tough covering of the ovary and begin to multiply. These cells can collect large amounts of blood and form what is called, appropriately, an ovarian blood cyst. These have been known to grow to the size of a hen's egg or even an orange, and as you can imagine, are usually very painful. Over time the collected blood darkens and for this reason the cysts are frequently called "chocolate cysts".

Endometriosis is a common problem among women and occurs in an estimated 10 to 20% of them during their reproductive years. The prevalence may be as high as 15 to 40% among infertile women. Although endometriosis is typically diagnosed between the ages of 25 and 35, the problem probably begins about the time that regular menstruation begins. Adolescents may experience symptoms such as severe cramping or discomfort, however, they are frequently ignored or written off as normal. A woman who has a mother or sister with endometriosis, has a risk of developing endometriosis that is 6 times greater than that of the general population. Other risk factors include having a menstrual cycle lengths of 27 days or less, early onset of menstrual periods, and periods lasting 7 or more days. Orgasm during the menstrual cycle has also been noted as a potential risk factor (linked to the retrograde menstruation theory).