This tissue lining the inside of the uterus is called the endometrium. Endometriosis is a gynecological disease that occurs when this tissue grows outside of the uterus on the surfaces of pelvic and abdominal organs. Endometriosis most commonly occurs on or under the ovaries, inside the fallopian tubes, or along the tissue lining the pelvis; in rare occasions, it grows in other parts of the body.
The tissue that is growing in unusual places still responds to a woman’s menstrual cycle and breaks down on a monthly basis. But, where menstrual blood flows out of the body (from the uterus and through the vagina), tissues associated with endometriosis are trapped inside the body. This causes internal bleeding and inflammation that can lead to pain and more serious complications.2
More than six million people have endometriosis in the U.S. It is most common among individuals in their 30s and 40s.
Causes of Endometriosis
There are several theories about the cause of endometriosis, including:
- Retrograde Menstruation: Menstrual blood containing endometrial cells flows backward up the fallopian tubes and into the pelvic cavity, where they become implanted and grow, leading to endometriosis.
- Embryonic Cell Growth: Embryonic cells that genetically should become the lining of the abdominal and pelvic cavities instead develop into endometrial cells during puberty.
- Surgical Scar Implantation: During a surgery, like a cesarean section or hysterectomy, endometrial cells may attach to the surgical incision site and grow, causing endometriosis.
- Endometrial Cell Transport: Endometrial cells may travel to other parts of the body through blood vessels or the lymphatic system and become implanted there.
- Immune System Disorders: As a result of a woman’s impaired immune system, endometrial cells that grow outside of the uterus may be able to be evade the body’s natural defenses, leading to endometriosis.
- Environmental Factors: There may be a connection between endometriosis and chemicals called dioxins, which come from environmental sources including pesticides, herbicides, industrial waste, and incineration.
In addition to these common theories, there are several risk factors for endometriosis including:
- Early menarche
- Delayed menopause
- Short menstrual cycles (less than 27 days)
- Heavy periods
- Never giving birth
- Low body mass index (BMI)
- Above average levels of estrogen for an extended period of time
- Reproductive tract abnormalities
- Relative with endometriosis
Symptoms of Endometriosis
- Pain in the abdomen, lower back, and pelvic areas right before and during a menstrual period
- Pain during and after intercourse
- Painful bowel movements or urination during menstrual periods
- Heavy menstrual/ premenstrual/ intermenstrual bleeding
- Intestinal upset during periods (including diarrhea, painful bowel movements, and/or constipation)
Some people don’t have any symptoms of endometriosis; for others, symptoms can or come and go, or get worse over time.
Complications of Endometriosis
The most common complication caused by endometriosis is infertility. Endometriosis impacts fertility by obstructing the fallopian tubes, thus preventing the egg from uniting with a sperm. In other cases, endometriosis can also damage the sperm or egg. Individuals at risk of endometriosis are encouraged to not delay in having children; however, people with mild to moderate endometriosis have been known to conceive and carry pregnancies to term.
There is also a correlation between individuals with endometriosis and the onset of ovarian cancer, as it occurs in higher than expected rates within people who have endometriosis.
Diagnosis of Endometriosis
Sometimes endometriosis can be detected during a pelvic exam. Your doctor may perform an ultrasound (a procedure that uses sound waves to make an image of internal organs) to look for a specific type of cyst that is common with endometriosis. An MRI may also be taken to more accurately determine the location and size of endometrial implants. 1
In some cases, diagnosis requires a laparoscopy because endometriosis can be mistaken for other conditions such as Pelvic Inflammatory Disease (PID), ectopic pregnancy, cysts, appendicitis, diverticulitis, Irritable Bowel Syndrome (IBS), and cancer.
During a laparoscopy, the patient is anesthetized and a thin viewing device (a “laparoscope”) is threaded into a small incision; this device is used to check for endometriosis and take a tissue sample, or biopsy. Often, the surgeon will destroy any visible endometrial lesions that are identified during the diagnosis process.
Treatment of Endometriosis
For mild pain, over-the-counter pain medications such as nonsteroidal anti-inflammatory drugs and applying a heating pad to the affected areas can help relieve discomfort.
Exercising regularly and engaging in relaxation techniques like yoga and meditation, can also relieve symptoms. Some studies have also shown that acupuncture reduces the pain caused by endometriosis.
Hormones are a widely used method to treat endometriosis and should be tried before more invasive surgical options. Using oral contraceptives, birth control patches, progestin-only medications (like Depo Provera), or vaginal rings minimize the growth of uterine tissue, and may provide relief from endometriosis symptoms. Some individuals with endometriosis use year-round oral contraceptives , in order to suppress menstrual cycles and further reduce endometriosis-related symptoms.1
Drugs that reduce the amount of estrogen in the body (Aromatase inhibitors and Gonadotropin-releasing hormone (Gn-RH) agonists and antagonists) can also be used as a form of treatment, This allows endometrial tissue to shrink, causing a sort of artificial menopause. Gn-RH medication must often be paired with a low dose of estrogen or progestin to counter the common side effects such as hot flashes and bone loss.
Operative laparoscopy is the most common surgery to remove endometrial growths and adhesions. The surgeon cuts tissue away with a scalpel or may use intense heat to destroy areas of endometriosis. About 40-80 percent of people have a recurrence of endometrial pain within two years of surgery.
Hysterectomy is a surgery that removes the uterus and is the last resort for treating endometriosis. If you are considering a hysterectomy to treat endometriosis, remember that there is a chance the endometriosis will recur, even after a hysterectomy. The removal of the uterus and ovaries will also trigger the onset of menopause, which carries along its own set of medical side effects as well. The NWHN believes that less-invasive treatment options should always be explored before hysterectomy is used to address endometriosis.
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- Mayo Clinic Website, Endometriosis, Rochester, MN: Mayo Clinic, March 23, 2019. Retrieved on July 8, 2019 from: https://www.mayoclinic.org/diseases-conditions/endometriosis/symptoms-causes/syc-20354656.
- Endometriosis Association, What is Endometriosis?, Milwaukee: Endometriosis Association, no date. Retrieved on July 8, 2019 from: https://endometriosisassn.org/about-endometriosis.
Updated July 2019