Endometriosis: Key Q&A

Reviewed By:
Joanne Poje Tomasulo, M.D., ACOG

How common is endometriosis?
According to the Centers for Disease Control and Prevention, more than 5 million women in the United States have endometriosis. This is about 10 to 15 percent of all women in their reproductive years. However, the exact incidence of the condition is likely even higher. This is because women without symptoms or fertility problems may have endometriosis without knowing it.

What is endometriosis?
Endometriosis is a condition in which the cells that form the tissue that lines the uterus, which is called the endometrium, grow in locations outside the uterus. Endometrial tissue consists of glands, blood cells and connecting tissue called stromal cells. The tissue responds to your monthly hormonal changes whether it is in your uterus or located elsewhere.

The displaced tissue of endometriosis, which is called endometrial implants or lesions, grows and expands as it would in your uterus. However, it cannot leave the body the way the uterine tissue does during menstruation. As a result, the implants can bleed into other areas or inflame other organs and form scar tissue or adhesions. This may result in severe pain and damage to your organs, especially your reproductive organs.

What do endometrial implants look like?
Endometrial implants begin microscopically small, often as clear lesions. With time, they become larger and darker and can take many shapes. The colors vary, ranging from red, brown or black to clear, white, yellow or pink. The prevailing color may depend on the blood supply, age of the lesion and other nearby tissue. Some endometrial lesions look like other scars or inflammations and may need an experienced surgeon to recognize them as endometriosis.

Where can endometriosis occur?
Endometrial implants usually occur in your pelvic region, including your ovaries, fallopian tubes, the lining of your pelvic cavity, on the outside of your uterus and on its ligaments and on your lymph nodes. Many women with endometriosis have lesions in more than one location. Endometriosis may sometimes occur in other parts of your abdomen, such as your rectum and bladder. In rare cases, endometrial tissue may be discovered in other body parts such as your arms, legs or lungs.

What causes endometriosis or increases your risk?
The cause of endometriosis is unknown. It is not completely understood if the endometrial tissue moves to other locations or develops there as a result of cell changes. Women at higher risk for endometriosis include those who have never given birth, those who have had female surgical procedures and those with menstrual periods that last longer than eight days.

Can endometriosis be prevented?
No. There are no known methods to prevent endometriosis. The disease usually continues unless it is interrupted by pregnancy or treated. It can recur with all treatments. At menopause, the symptoms may lessen. The effect of hormone replacement therapy in women with endometriosis who reach natural menopause is unknown.

What are the symptoms of endometriosis?
The symptoms of endometriosis may include pain during menstruation or sexual intercourse, painful urination or bowel movements during menstruation, heavy menstrual bleeding or any premenstrual bleeding. Sometimes women experience chronic pain. Some women have no symptoms.

How is a diagnosis of endometriosis confirmed?
The diagnosis is usually confirmed by laparoscopy. During this procedure, an incision is made in your abdomen and a small lighted viewing device is inserted into your pelvis. The surgeon can look for endometrial implants and possibly remove them at the same time by cutting them or burning them off with a laser or cautery. A cautery is a heating device. Endometriosis can also be diagnosed with an open abdominal surgery called a laparotomy, but is less common in the United States and more invasive. Surgeons can also remove lesions during a diagnostic laparotomy.

Is endometriosis always treated with a hysterectomy?
No. Treatment for endometriosis can be medical or surgical, depending on your age, symptoms and whether or not you plan to become pregnant. Hysterectomy is considered a treatment of last resort for women in their reproductive years. It is likely to end the symptoms, but also ends the opportunity for pregnancy. Women who have hysterectomies with removal of the ovaries reach menopause immediately and may experience related problems, such as hot flashes, night sweats, insomnia and osteoporosis. This surgical menopause usually causes more severe symptoms than natural menopause does.

What are the non-surgical treatment options for endometriosis?
Pain caused by endometriosis can be treated with pain killers, or analgesics. These medications are used to alleviate symptoms, but do not have an impact on the underlying condition. Endometrial lesions also respond to hormones, including the estrogen and progestin usually found in birth control pills. Therefore, these medications may lessen the severity of symptoms. Other hormone therapies can produce the same effects as menopause or pregnancy. The goal is to stop menstruation, which can take several months. Hormonal treatments may minimize endometrial symptoms and shrink implants, but cannot affect any scarring or adhesions that have already formed. They are rarely effective in women with severe endometriosis.

When is endometriosis treated surgically?
Doctors consider surgery for endometriosis when there are advanced adhesions and scarring or when medical therapy has not alleviated symptoms, such as severe pain.

What is the most common surgical treatment for endometriosis?
Conservative surgery is the preferred surgical treatment for endometriosis. It involves removing the endometrial implants while maintaining your reproductive organs. The disease can be diagnosed and treated at the same time. Surgeons sedate you with anesthesia and perform a laparoscopy or laparotomy to remove the implants by heat, laser or cutting them out. Removing the implants by cutting them out is also called excision. Excision is the preferred method so the lesions can be examined in a biopsy. Surgeons also correct the positions of any organs, such as ovaries, that have become displaced because of the adhesions.

Is treatment always effective?
Not always. With all endometriosis treatments, the condition may recur and the pain may return, although this is uncommon after hysterectomy. There is no cure for endometriosis. You may consult with your doctor to determine the best course of treatment for the disease, its symptoms and your fertility. Cost of treatment may be a consideration. Some hormone therapies such as GnRH agonists are expensive, as are repeated surgeries.