Endometriosis is a disorder of the female reproductive system. In endometriosis, the endometrium, which normally lines your uterus, grows in other places as well. Most often, this growth is on your fallopian tubes, ovaries or the tissue lining your pelvis. When endometrial tissue is located elsewhere in your body, it continues to act as it normally would during a menstrual cycle: It thickens, breaks down and bleeds each month. Because there's nowhere for the blood from this displaced tissue to exit your body, it becomes trapped, and surrounding tissue can become irritated. Trapped blood may lead to cysts, scar tissue and adhesions — abnormal tissue that binds organs together. This process can cause pelvic pain, especially during your period. Endometriosis also can cause fertility problems.
Complications of Endometriosis
The main complication of endometriosis is impaired fertility. Approximately one-third to one-half of women who have endometriosis has difficulty getting pregnant.
For pregnancy to occur, an egg must be released from an ovary, travel through the fallopian tube, become fertilized by a sperm cell and attach itself to the uterine wall to begin development. Endometriosis can produce adhesions that can trap the egg near the ovary. It may inhibit the mobility of the fallopian tube and impair its ability to pick up the egg. In most cases, however, endometriosis probably interferes with conception in more complex ways.
Despite these possible complications, many women with endometriosis are still able to conceive. It may take them a little longer to get pregnant, but most women with mild to moderate endometriosis can become pregnant. During pregnancy, most women have no signs or symptoms of endometriosis.
Doctors sometimes advise women with endometriosis not to delay having children because endometriosis tends to worsen with time. The longer you have endometriosis, the greater your chance of becoming infertile.
Although cancerous changes may occur in endometrial implants, the rate of cancer in this tissue hasn't been shown to be higher than that in other tissues. Having endometriosis doesn't increase your risk of uterine cancer or ovarian cancer.
Causes of Endometriosis
The cause of endometriosis remains uncertain. Experts are studying the roles that hormones and the immune system play in this condition.
One theory holds that menstrual blood containing endometrial cells flows back through the fallopian tubes, takes root and grows. Another hypothesis proposes that the bloodstream carries endometrial cells to other sites in the body. Still another theory speculates that a predisposition toward endometriosis may be carried in the genes of certain families. A faulty immune response also may contribute to the development of endometriosis.
Other researchers believe that certain cells present within the abdomen in some women retain their ability to become endometrial cells. These same cells were responsible for the growth of the women's reproductive organs at the embryo stage. It's believed that genetic or environmental influences in later life allow these cells to give rise to endometrial tissue outside the uterus.
Signs & Symptoms of Endometriosis
Endometriosis can be mild, moderate or severe, and without treatment, it tends to get worse over time. Some women with endometriosis have no signs and symptoms at all, and the disease is discovered only when bits of endometrial tissue (implants) are found outside the uterus during an unrelated operation, such as a tubal ligation. Other women may experience one or more of the following signs and symptoms:
Painful periods (dysmenorrhea). Pelvic pain and cramping may begin before and extend several days into your period and may include lower back and abdominal pain. Severity of pain isn't necessarily a reliable indicator of the extent of the condition. Some women with mild endometriosis have intense pain, while others with more severe scarring may have little pain or even no pain at all.
Pelvic pain at other times. You may experience pelvic pain during ovulation, a sharp pain deep in the pelvis during intercourse, or pain during bowel movements or urination.
Excessive bleeding. You may experience occasional heavy periods (menorrhagia) or bleeding between periods (menometrorrhagia).
Infertility. Endometriosis is first diagnosed in some women who are seeking treatment for infertility.
Endometriosis is sometimes mistaken for other conditions that can cause pelvic pain, such as pelvic inflammatory disease (PID) or ovarian cysts. It may be confused with irritable bowel syndrome (IBS), a condition that causes bouts of diarrhea, constipation and abdominal cramping. IBS can accompany endometriosis, which can complicate the diagnosis.
Diagnosis of Endometriosis
To diagnose endometriosis and other conditions that can cause pelvic pain, your doctor will ask you to describe your symptoms, including the location of your pain and when it occurs.
Tests to check for physical clues of endometriosis include:
Pelvic exam. During a pelvic exam, your doctor manually feels (palpates) areas in your pelvis for abnormalities, such as cysts on your reproductive organs or scars behind your uterus. Often it's not possible to feel small areas of endometrial implantation, unless they've caused a cyst to form.
Ultrasound. During a vaginal ultrasound, a wand-shaped scanner (transducer) is inserted into your vagina. In an ultrasound of the pelvis via the abdomen, a small scanner is moved across your abdomen. Both tests use sound waves to provide a video image of your reproductive organs. Ultrasound imaging won't definitively tell your doctor whether or not you have endometriosis, but it is a useful tool for identifying cysts associated with endometriosis (endometriomas).
Laparoscopy. The only way for your doctor to know for certain that you have endometriosis is by looking inside your abdomen (direct visualization) for signs of endometrial tissue. Commonly, this is accomplished during a minor surgical procedure called laparoscopy.
You receive a general anesthetic before the procedure begins. Using a special needle, your abdomen is expanded (distended) with carbon dioxide gas so that the reproductive organs are easier to see. A tiny incision is made near your navel, and a slender viewing instrument (laparoscope) is inserted. By moving the laparoscope around, the surgeon can view the pelvic and other abdominal organs, looking for signs of endometrial implants.
If you have endometriosis, laparoscopy will tell you and your doctor the extent, size and location of endometrial tissue outside your uterus. This information will help your doctor guide you through treatment options. Sometimes, symptoms and signs are obvious enough that a laparoscopy isn't necessary.
Blood test. Cancer antigen 125 (CA 125) is a blood test often used to detect tumor markers for certain cancers, but it's also used to detect a certain protein found in the blood of women with endometriosis. Although CA 125 commonly reveals an elevation in such blood protein in women with advanced endometriosis, it's not as sensitive to mild or moderate disease. As with cancer, CA 125 doesn't perform well as a screening test for endometriosis because it's least sensitive when the disease is in its earliest stages.
Treatments of Endometriosis
Treatment for endometriosis is usually with medications or surgery. The approach you and your doctor choose depends on the severity of your signs and symptoms and whether you hope to become pregnant. Generally, doctors recommend trying conservative treatment approaches first, opting for surgery as a last resort.
Your doctor may recommend that you take an over-the-counter pain reliever, such as ibuprofen (Advil, Motrin IB, others), to help ease painful menstrual cramps. However, if you find that taking the maximum dose doesn't provide full relief, you may need to try another treatment to manage your signs and symptoms.
Supplemental hormones are effective in reducing or eliminating the pain of endometriosis. That's because the rise and fall of hormones during a woman's menstrual cycle causes endometrial implants to thicken, break down and bleed. In fact, if hormonal therapy has little to no effect on your symptoms, consider questioning the diagnosis of endometriosis or its relationship to your symptoms.
Hormonal therapies used to treat endometriosis include:
Hormonal contraceptives. Birth control pills, patches and the vaginal ring help control the hormones responsible for the buildup of endometrial tissue each month. Most women have lighter and shorter menstrual flow when they're using a hormonal contraceptive. Using hormonal contraceptives — especially continuous cycle regimens — can reduce or eliminate the pain of mild to moderate endometriosis.
Gonadotropin-releasing hormone (Gn-RH) agonists and antagonists. These drugs block the production of ovarian-stimulating hormones. This action prevents menstruation and dramatically lowers estrogen levels, causing endometrial implants to shrink. Gn-RH agonists and antagonists can force endometriosis into remission during the time of treatment and sometimes for months or years afterward. These drugs create an artificial menopause that can sometimes lead to troublesome side effects, such as hot flashes and vaginal dryness. A low dose of estrogen may be taken along with these drugs to decrease such side effects.
Danazol. Another drug that blocks the production of ovarian-stimulating hormones, preventing menstruation and the symptoms of endometriosis, is danazol. In addition, it suppresses the growth of the endometrium. However, danazol may not be the first choice because it can cause unwanted side effects, such as acne and facial hair.
Medroxyprogesterone (Depo-Provera). This injectable drug is effective in halting menstruation and the growth of endometrial implants, thereby relieving the signs and symptoms of endometriosis. Its side effects can include weight gain, decreased bone production and depressed mood.
Aromatase inhibitors. These agents, known for their effectiveness in treating breast cancer, also may be useful for endometriosis. Aromatase inhibitors work by blocking the conversion of hormones such as androstenedione and testosterone into estrogen and by blocking the production of estrogen from endometrial implants themselves. This deprives endometriosis of the estrogen it needs to grow. Early studies suggest that aromatase inhibitors are at least as good as other hormonal approaches and may be better tolerated.
Hormonal therapies aren't a permanent fix for endometriosis. It's possible that you could experience a recurrence of your symptoms after stopping treatment.
If you have endometriosis and are trying to become pregnant, surgery to remove implants may increase your chances of success. If you have severe pain from endometriosis, you may also benefit from surgery.
Conservative surgery removes endometrial growths, scar tissue and adhesions without removing your reproductive organs. Your doctor may do this procedure laparoscopically, or through traditional abdominal surgery in more extensive cases. In laparoscopic surgery, a slender viewing instrument (laparoscope) is inserted through a small incision near your navel. Guided by the laparoscope, your doctor inserts other instruments through another small incision to remove endometrial implants. Such instruments might include a laser, small surgical instruments or a cautery — an instrument that destroys tissue with heat.
Assisted reproductive technologies to help you become pregnant are sometimes preferable to conservative surgery, and doctors often suggest these approaches if conservative surgery is ineffective.
In severe cases of endometriosis, a total hysterectomy and the removal of both ovaries may be the best treatment. Hysterectomy alone is also effective, but removing the ovaries ensures that endometriosis will not return. Either type of surgery is typically considered a last resort, especially for women still in their reproductive years. You can't get pregnant after a hysterectomy.
Prevention of Endometriosis
Because the causes of endometriosis remain elusive, no definite techniques to manage the risk of endometriosis have been developed. Although it appears that women who have given birth are less likely to develop endometriosis than are women who have not, many other factors play a more important role in the decision to have a child.
When to seek Medical Advice
See your doctor if you have signs and symptoms that may indicate endometriosis. The cause of chronic or severe pelvic pain may be difficult to pinpoint. But discovering the problem early may help you avoid unnecessary complications and pain.