What is Endometriosis?
The endometrium is the inside lining of the uterus. When the tissue usually begins growing, it may lead to scarring and the formation of cysts. Endometriosis is a disease in which bits of endometrial-like tissue grow outside the uterus, usually somewhere in the abdominal cavity. The most common sites of endometriosis are:
- Ligaments that support the uterus
- Outside surface of the uterus
- Fallopian tubes
- Interior tissue between the rectum and vagina
- Pelvic cavity lining
- It may also grow in the rectum, vagina, intestines, bladder and other adjacent areas
- In very rare cases, endometriosis occurs outside the abdomen
It can be a progressive, often debilitating disease, affecting 10 to 15 percent of women during their reproductive years. It accounts for 25 percent of laparotomies (laparoscopic procedures) performed by gynecologists. Among gynecologic disorders, endometriosis is surpassed in frequency only by leiomyomas (benign tumors derived from smooth muscle, most commonly in the uterus. Also called fibroids or fibroid tumors).
Scientists do not know the exact cause of endometriosis. However, there are a variety of reasons about why it occurs. Some theories propose...
- The disease is a result of blood and menstrual tissue from the uterus flowing backward into the fallopian tubes. This process is called retrograde menstruation. Theoretically, the endothelium cells attach to organs and tissues outside the uterus, in the abdomen and elsewhere.
- However, studies have shown that almost all women experience retrograde menstruation. Yet most women do not get endometriosis.
- Some women are born with endometrial cells in their abdominal tissues that are stimulated into endometriosis after puberty.
- Endometrial tissue migrates from the uterus to other locations via blood or lymph vessels. This would explain the cases in which endometrial tissue has been discovered in unusual places, like the lungs.
- Transplanting of endometrial tissue may accidentally occur during surgery. This would help explain why endometriosis has been found in the scar tissue of women who have had abdominal surgery.
- Environmental pollution, including a possible link between the disease and dioxin.
- Endometriosis does seem to run in families, and may be caused by a defect in a woman's immune system. A woman whose mother or sister has endometriosis finds her own chances of getting the disease are increased as much as tenfold.
- That the more menstrual cycles a woman women gave birth more frequently, and at a younger age, their frequent pregnancies meant they had fewer menstrual cycles. Women today who postpone pregnancy and have fewer children have significantly more cycles.
The Female Reproductive System
The uterus is a pear-shaped organ located between the bladder and lower intestine, and consists of two parts: the body and the cervix.
Structures called fallopian tubes come off each side of the uterus's body. At the end of each is an ovary.
When a woman is pregnant the walls of the uterus, which are normally the size of a fist, are pushed apart as the fetus grows. The inner lining of the uterus, the endometrium, thickens and becomes enriched with blood vessels to house and support the growing fetus.
During a female's normal period, the endometrium is shed as part of the menstrual flow and passed through the lower third of the uterus, through an opening called the os, and into the vagina.
Six key hormones regulate the reproductive system in the following way...
- The brain's hypothalamus releases gonadotropin-releasing hormone (GnRH).
- GnRH stimulates the pituitary gland, which produces follicle- stimulating hormone (FSH) and luteinizing hormone (LH).
- FSH and LH cause the overies to secrete estrogen, progesterone and testosterone.
Common locations for these endometrial tissue implants are the ovaries, the fallopian tubes and the cavities between the uterus and the rectum or the uterus and the bladder. (These cavities are called cul-de-sacs.) The implants are also called "lesions," "nodules" or "growths." Sometimes the implants result in bands of fibrous scar tissue that bind together pelvic organs. Although the implants usually appear in the pelvic area, they have been found in the brain, lungs, arms and thighs. To further confound researchers, men have been diagnosed with endometriosis in rare cases.
The disease takes its name from the endometrium, the lining of the uterus. Normally, each month when a woman ovulates, the ovaries release doses of estrogen and progesterone. These hormones trigger the uterus to swell with blood and tissue, building a soft nest for the egg. But if the egg is not fertilized, the body decreases production of certain hormones causing the uterus to shed its lining. The blood and tissue exit the woman's body through the uterus, cervix and vagina during menstruation, which occurs generally every four weeks or so. After several days or a week of bleeding, the cycle begins again.
But in women with endometriosis, this monthly pattern becomes more complex. Implants of endometrial tissue that are growing in other parts of the body respond to the hormones? orders. So when the hormones cause the uterus lining to swell, so do the implants. And at the end of the month, when the tissue inside the uterus is directed to break apart, the implants break apart, too, and bleed. But unlike the tissue in the uterus, which exits through the vagina, the implants have nowhere to go. They tend to irritate other nearby tissues, which may become swollen or inflamed. Sometimes this inflammation creates scar tissue.