Endometriosis is the growth of cells similar to those that form the inside of the uterus (endometrial cells), but in a location outside of the uterus. Endometrial cells are the same cells that are shed each month during menstruation. The cells of endometriosis attach themselves to tissue outside the uterus and are called endometriosis implants.
These implants are most commonly found on the ovaries, the Fallopian tubes, outer surfaces of the uterus or intestines, and on the surface lining of the pelvic cavity.
They can also be found in the vagina, cervix, and bladder, although less commonly than other locations in the pelvis. Rarely, endometriosis implants can occur outside the pelvis, on the liver, in old surgery scars, and even in or around the lung or brain. Endometrial implants, while they can cause problems, are benign (not cancerous).
Who is affected by endometriosis?
This disease affects women in their reproductive years – the exact prevalence is not known, since many women may have the condition and have no symptoms. It is estimated to affect over one million women (estimates range
from 3% to 18% of women) in the United States. It is one of the leading causes of pelvic pain and reasons for laparoscopic surgery and hysterectomy. While most cases are diagnosed in women aged around 25-35 years, endometriosis has been reported in girls as young as 11 years of age. It is rare in postmenopausal women and more commonly found in white women as compared with African American and Asian women. Studies further suggest that endometriosis is most common in taller, thin women with a low body mass index (BMI). Delaying pregnancy until an older age is also believed to increase the risk of developing endometriosis.
The cause of endometriosis is unknown. One theory is that the endometrial tissue is deposited in unusual locations by the backing up of menstrual flow into the Fallopian tubes and the pelvic and abdominal cavity during menstruation (termed retrograde menstruation).
The cause of retrograde menstruation is not clearly understood. But retrograde menstruation cannot be the sole cause of endometriosis. Many women have retrograde menstruation in varying degrees, yet not all of them develop endometriosis.
Another possibility is that areas lining the pelvic organs possess primitive cells that are able to grow into other forms of tissue, such as endometrial cells.
It is also likely that direct transfer of endometrial tissues during surgery may be responsible for the endometriosis implants sometimes seen in surgical scars (for example, episiotomy or Cesarean section scars). Transfer of endometrial cells via the bloodstream or lymphatic system is the most likely explanation for the rare cases of endometriosis that develop in the brain and other organs distant from the pelvis.
Finally, some studies have shown alternations in the immune response in women with endometriosis, which may affect the body’s natural ability to recognize and destroy any misdirected growth of endometrial tissue.
You are more likely to develop endometriosis if you: * began getting your period at an early age * have heavy periods * have periods that last more than seven days * have a short monthly cycle (27 days or less) * have a close relative (mother, aunt, sister) with endometriosis Some studies suggest that you may lower your chances of developing endometriosis if you exercise regularly and avoid alcohol and caffeine.
Most women who have endometriosis, in fact, do not have symptoms. Of those who do experience symptoms, the common symptoms are pain (usually pelvic) and infertility. Pelvic pain usually occurs during or just before menstruation and lessens after menstruation. Some women experience pain or cramping with intercourse, bowel movements and/or urination.
Even pelvic examination by a doctor can be painful. The pain intensity can change from month to month, and vary greatly among women. Some women experience progressive worsening of symptoms, while others can have resolution of pain without treatment.
Pelvic pain in women with endometriosis depends partly on where the implants of endometriosis are located:
Deeper implants and implants in areas with many pain-sensing nerves may be more likely to produce pain.
The implants may also produce substances that circulate in the bloodstream and cause pain.
Lastly, pain can result when endometriosis implants form scars. There is no relationship between severity of pain and how widespread the endometriosis is.
This disease can be one of the reasons for infertility in otherwise healthy couples. When laparoscopic examinations are performed for infertility evaluations, endometrial implants can be found in some of these patients, many of whom may not have painful symptoms of endometriosis. The reasons for a decrease in fertility are not completely understood, but might be due to both anatomic and hormonal factors. The presence of endometriosis may involve masses of tissue or scarring (adhesions) within the pelvis that may distort normal anatomical structures, such as Fallopian tubes, which transport the eggs from the ovaries.
Alternatively, endometriosis may affect fertility through the production of hormones and other substances that have a negative effect on ovulation, fertilization of the egg, and/or implantation of the embryo. Other symptoms include:
• lower abdominal pain,
• diarrhea and/or constipation,
• low back pain,
• irregular or heavy menstrual bleeding, or
• blood in the urine.
Rare symptoms include chest pain or coughing blood due to endometriosis in the lungs and headache and/or seizures due to endometriosis in the brain.
Endometriosis can be treated with medications and/or surgery and/or natural remedies. The goals of endometriosis treatment may include pain relief and/or enhancement of fertility.
Endometriosis at A Glance
- Endometriosis is the growth of endometrial tissue (cells that normally grow inside the uterus (womb), but in a location outside of the uterus. It is most commonly found on other organs of the pelvis.
- The exact cause of this disease has not been identified.
- Common in women who are experiencing infertility than in fertile women, but the condition does not fully prevent conception.
- Most women with this condition have no symptoms, in which case therapy is neither appropriate nor necessary.
- Pelvic pain during menstruation or ovulation can be a symptom of endometriosis, but may also occur in normal women.
- Diagnosis is confirmed by surgery – usually laparoscopy.
- Treatment includes medication and surgery for both pain relief and treatment of infertility if pregnancy is desired.
(Author: Melissa Conrad Stoppler; Editor: William C. Shiel, Jr.)
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