Also found in: Dictionary, Thesaurus, Acronyms, Encyclopedia, Wikipedia.
Related to endometriosis: endometrial cancer




Endometriosis is a condition in which bits of the tissue similar to the lining of the uterus (endometrium) grow in other parts of the body. Like the uterine lining, this tissue builds up and sheds in response to monthly hormonal cycles. However, there is no natural outlet for the blood discarded from these implants. Instead, it falls onto surrounding organs, causing swelling and inflammation. This repeated irritation leads to the development of scar tissue and adhesions in the area of the endometrial implants.


Endometriosis is estimated to affect 7% of women of childbearing age in the United States. It most commonly strikes between the ages of 25 and 40. Endometriosis can also appear in the teen years, but never before the start of menstruation. It is seldom seen in postmenopausal women.
Endometriosis was once called the "career woman's disease" because it was thought to be a product of delayed childbearing. The statistics defy such a narrow generalization; however, pregnancy may slow the progress of the condition. A more important predictor of a woman's risk is if her female relatives have endometriosis. Another influencing factor is the length of a woman's menstrual cycle. Women whose periods last longer than a week with an interval of less than 27 days between them seem to be more prone to the condition.
Endometrial implants are most often found on the pelvic organs—the ovaries, uterus, fallopian tubes, and in the cavity behind the uterus. Occasionally, this tissue grows in such distant parts of the body as the lungs, arms, and kidneys. Newly formed implants appear as small bumps on the surfaces of the organs and supporting ligaments and are sometimes said to look like "powder burns." Ovarian cysts may form around endometrial tissue (endometriomas) and may range from pea to grapefruit size. Endometriosis is a progressive condition that usually advances slowly, over the course of many years. Doctors rank cases from minimal to severe based on factors such as the number and size of the endometrial implants, their appearance and location, and the extent of the scar tissue and adhesions in the vicinity of the growths.

Causes and symptoms

Although the exact cause of endometriosis is unknown, a number of theories have been put forward. Some of the more popular ones are:
  • Implantation theory. Originally proposed in the 1920s, this theory states that a reversal in the direction of menstrual flow sends discarded endometrial cells into the body cavity where they attach to internal organs and seed endometrial implants. There is considerable evidence to support this explanation. Reversed menstrual flow occurs in 70-90% of women and is thought to be more common in women with endometriosis. However, many women with reversed menstrual flow do not develop endometriosis.
  • Vascular-lymphatic theory. This theory suggests that the lymph system or blood vessels (vascular system) is the vehicle for the distribution of endometrial cells out of the uterus.
  • Coelomic metaplasia theory. According to this hypothesis, remnants of tissue left over from prenatal development of the woman's reproductive tract transforms into endometrial cells throughout the body.
  • Induction theory. This explanation postulates that an unidentified substance found in the body forces cells from the lining of the body cavity to change into endometrial cells.
In addition to these theories, the following factors are thought to influence the development of endometriosis:
  • Heredity. A woman's chance of developing endometriosis is seven times greater if her mother or sisters have the disease.
  • Immune system function. Women with endometriosis may have lower functioning immune systems that have trouble eliminating stray endometrial cells. This would explain why a high percentage of women experience reversed menstrual flow while relatively few develop endometriosis.
  • Dioxin exposure. Some research suggests a link between the exposure to dioxin (TCCD), a toxic chemical found in weed killers, and the development of endometriosis.
While many women with endometriosis suffer debilitating symptoms, others have the disease without knowing it. Paradoxically, there does not seem to be any relation between the severity of the symptoms and the extent of the disease. The most common symptoms are:
  • Menstrual pain. Pain in the lower abdomen that begins a day or two before the menstrual period starts and continues through to the end is typical of endometriosis. Some women also report lower back aches and pain during urination and bowel movement, especially during their periods.
  • Painful sexual intercourse. Pressure on the vagina and cervix causes severe pain for some women.
  • Abnormal bleeding. Heavy menstrual periods, irregular bleeding, and spotting are common features of endometriosis.
  • Infertility. There is a strong association between endometriosis and infertility, although the reasons for this have not been fully explained. It is thought that the build up of scar tissue and adhesions blocks the fallopian tubes and prevents the ovaries from releasing eggs. Endometriosis may also affect fertility by causing hormonal irregularities and a higher rate of early miscarriage.


If a doctor suspects endometriosis, the first step will be to perform a pelvic exam to try to feel if implants are present. Very often there is no strong evidence of endometriosis from a physical exam. The only way to make a definitive diagnosis is through minor surgery called a laparoscopy. A laparoscope, a slender scope with a light on the end, is inserted into the woman's abdomen through a small incision near her belly button. This allows the doctor to examine the internal organs for endometriotic growths. Often, a sample of tissue is taken for later examination in the laboratory. Endometriosis is sometimes discovered when a woman has abdominal surgery for another reason such as tubal ligation or hysterectomy.
Various imaging techniques such as ultrasound, computed tomography scan (CT scan), or magnetic resonance imaging (MRI) can offer additional information but aren't useful in making the initial diagnosis. A blood test may also be ordered because women with endometriosis have higher levels of the blood protein CA125. Testing for this substance before and after treatment can predict a recurrence of the disease, but the test is not reliable as a diagnostic tool.


How endometriosis is treated depends on the woman's symptoms, her age, the extent of the disease, and her personal preferences. The condition cannot be fully eradicated without surgery. Conservative treatment focuses on managing the pain, preserving fertility, and delaying the progress of the condition.

Pain relief

Over-the-counter pain relievers such as aspirin and acetaminophen (Tylenol) are useful for mild cramping and menstrual pain. Prescription-strength and over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Motrin, Advil) and naproxen (Naprosyn), are also effective. If pain is severe, a doctor may prescribe narcotic medications, although these can be addicting and are rarely used.

Hormonal treatments

Hormonal therapies effectively tame endometriosis but also act as contraceptives. A woman who is hoping to become pregnant would take these medications for a period of time, then try to conceive within several months of discontinuing treatment.
  • Oral contraceptives. Continuously taking estrogen-progestin pills tricks the body into thinking it is pregnant. This state of pseudopregnancy means reduced pelvic pain and a temporary withering of endometrial implants.
  • Danazol (Danocrine) and gestrinone are synthetic male hormones that lower estrogen levels, prevent menstruation, and shrink endometrial tissues. On the downside, they lead to weight gain and menopause-like symptoms, and cause some women to develop masculine characteristics.
  • Progestins. Medroxyprogesterone (Depo-Provera) and related drugs may also be used in treating endometriosis. They have been proven effective in minimizing pain and halting the progress of the condition, but are rarely used because of the high rate of side effects.
  • Gonadotropin-releasing hormone (GnHR) agonists. These estrogen-inhibiting drugs successfully limit pain and prevent the growth of endometrial implants. They can cause menopause symptoms, however, and doses have to be regulated to prevent bone loss associated with low estrogen levels.


Removing the uterus, ovaries, and fallopian tubes is the only permanent method of eliminating endometriosis. This is an extreme measure that deprives a woman of her ability to bear children and forces her body into menopause. Endometrial implants and ovarian cysts can be removed with laser surgery performed through a laparoscope. For women with minimal endometriosis, this technique is usually successful in reducing pain and slowing the condition's progress. It may also help infertile women increase their chances of becoming pregnant.

Alternative treatment

Although severe endometriosis should not be self-treated, many women find they can help their condition through alternative therapies. Taking vitamin B complex combined with vitamins C, E, and the minerals calcium, magnesium, and selenium can help the depression and lack of energy that may accompany endometriosis. B vitamins also counteract the side effects of hormonal drugs. Other women have found relief when they turned to a macrobiotic diet. Less extreme diets that cut out sugar, salt, and processed foods are sometimes helpful, as well. Mind-body therapies such as relaxation and visualization help women cope with pain. Other avenues to combat pain include acupuncture and biofeedback techniques. Still other women report positive results after being treated by chiropractors or homeopathic doctors.


Most women who have endometriosis have minimal symptoms and do well. Overall, endometriosis symptoms come back in an average of 40% of women over the five years following treatment. With hormonal therapy, pain returned after five years in 37% of patients with minimal symptoms and 74% of those with severe cases. The highest success rate from conservative treatment followed complete removal of implants using laser surgery. Eighty percent of these women were still pain-free five years later. In cases that don't respond to these treatments, a woman and her doctor may consider surgery to remove her reproductive organs.


There is no proven way to prevent endometriosis. One study, however, indicated that girls who begin participating in aerobic exercise at a young age are less likely to develop the condition.



Endometriosis Association International Headquarters. 8585 North 76th Place, Milwaukee, WI 53223. (800) 992-3636. http://EndometriosisAssn.org.

Key terms

Adhesions — Web-like scar tissue that may develop as a result of endometriosis and bind organs to one another.
Dioxin — A toxic chemical found in weed killers that has been linked to the development of endometriosis.
Endometrial implants — Growths of endometrial tissue that attach to organs, primarily in the pelvic cavity.
Endometrium — The tissue lining the uterus that grows and sheds each month during a woman's menstrual cycle.
Estrogen — A female hormone that promotes the growth of endometrial tissue.
Hormonal therapy — Use of hormone medications to inhibit menstruation and relieve the symptoms of endometriosis.
Laparoscopy — A diagnostic procedure for endometriosis performed by inserting a slender, wand-like instrument through a small incision in the woman's abdomen.
Menopause — The end of a woman's menstrual periods when the body stops making estrogen.
Retrograde menstruation — Menstrual flow that travels into the body cavity rather than being expelled through the uterus.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.


a condition in which tissue more or less perfectly resembling the endometrium occurs outside the uterine cavity, usually in the pelvic cavity. adj., adj endometriot´ic.
Cause. Currently the cause of endometriosis is unknown. Researchers propose three possible causes: (1) the expulsion of endometrial tissue during menstruation upward through the fallopian tubes and into the pelvic cavity, where it is implanted on the ovaries or peritoneum, (2) a hormonal change or other event that triggers transformation of coelomic epithelium to endometrial endothelium, and (3) a combination of these two in which transported endometrium chemically induces undifferentiated mesenchymal cells to form endometrial tissue. Women may be asymptomatic, and symptoms vary among women and in one woman over time. Symptoms may include secondary dysmenorrhea, dyspareunia, abnormal bleeding, and impaired fertility due to adhesions.
Treatment. Therapy is based on the age of the patient, her desire for pregnancy, and the extent of the endometrial growth. In young women with mild disease, combination oral contraceptives are often used. In more advanced cases, hormonally induced menopause may be indicated, because endometriosis regresses with menopause. In older women and in cases of extensive growth, surgical treatment is indicated. Conservative surgical treatment includes laparoscopy for lysis of adhesions and laser vaporization of endometrial lesions.
Common sites of endometriosis. From McKinney et al., 2000.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.


(en'dō-mē'trē-ō'sis), [MIM*131200]
Ectopic occurrence of endometrial tissue, frequently forming cysts containing altered blood.
[endometrium + -osis, condition]
Farlex Partner Medical Dictionary © Farlex 2012


A condition, usually resulting in pain and dysmenorrhea, that is characterized by the abnormal occurrence of functional endometrial tissue outside the uterus.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.


A condition affecting up to 50% of women, which is defined as the presence of functioning endometrial glands and stroma outside of uterine cavity, occurring (in descending order of frequency) in: ovaries, broad ligaments, rectovaginal septum, umbilical scars, intestine, lungs, breast; laparoscopic resection or ablation of minimal lesions increased fecundity.

Clinical findings
Often accompanied by dysmenorrhoea, cyclical pain, low back pain, thigh pain, hypermenorrhoea, repeated miscarriages, infertility, bleeding per rectum or bladder. Regional swelling with vicarious ectopic bleeding parallels menses.

Surgery if anatomy is distorted; TAH-BSO is definitive therapy.

Endometriosis is associated with future development of cancer.

Malignancy in endometriosis
Malignancy can arise in the epithelium (e.g., clear-cell or endometrioid carcinomas), stroma (e.g., endometrial stromal sarcoma, MMMT, adenosarcoma), or in other lesions (e.g., borderline tumours, endometrioid adenofibroma). Cancer allegedly occurs in up to 10% of cases.

Endometriosis, criteria and comments
• Active (functional) or inactive.
• Metaplastic changes—ciliated, hobnail, mucinous or squamous.

• Usually readily apparent.
• May be inconspicuous cuff.
• Spiral arterioles, haemosiderin, CD10.
• Decidualisation.
• Myxoid change.
• Smooth muscle metaplasia/elastosis.

• Pigmented histiocytes.
• Pseudoxanthomatous.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.


Endometrial implants Gynecology A condition affecting up to 50% of ♀, defined as the presence of functioning endometrial glands and stroma outside of uterine cavity, occurring, in descending order of frequency, the ovaries, broad ligaments, rectovaginal septum, umbilical scars, intestine, lungs, etc Clinical Often accompanied by dysmenorrhea, cyclical pain, low back pain, thigh pain, hypermenorrhea, repeated miscarriages, infertility; bleeding per rectum or bladder; regional swelling with vicarious ectopic bleeding parallels menses Evaluation Laparoscopy Management Surgery if anatomy is distorted; TAH-BSO is definitive therapy; laparoscopic resection or ablation of minimal lesions ↑ fecundity ♀
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.


Ectopic occurrence of endometrial tissue, frequently forming cysts containing altered blood.
[endometrium + -osis, condition]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012


(en?do-me?tre-o'sis ) [ endo- + ¹metro- + osis]
Enlarge picture
The presence of functioning ectopic endometrial glands and stroma outside the uterine cavity. The endometrial tissue invades other tissues and spreads by local extension, intraperitoneal seeding, and lymphatic and vascular routes. The endometrial implants may be present in almost any area of the body although generally they are confined to the pelvic area. In the U.S. this condition is estimated to occur in 10% to 15% of actively menstruating women between the ages of 25 and 44. Estimates are that 25% to 35% of infertile women are affected. Women whose mothers or sisters have endometriosis are 6 times more likely to develop the condition than those with no family history. Postmenopausal women on estrogen replacement therapy also can develop endometriosis. If a woman has had a history of endometriosis, she may develop it when treated with menopausal estrogen replacement. The fallopian tubes are common sites of ectopic implantation. Ectopic endometrial cells respond to the same hormonal stimuli as does the uterine endometrium. The cyclic bleeding and local inflammation surrounding the implants may cause fibrosis, adhesions, and tubal occlusion. Infertility may result. Synonym: endomyometritis See: illustration


Although the cause is unknown, hypotheses are that either endometrial cell migration occurs during fetal development, or the cells shed during menstruation are expelled through the fallopian tubes to the peritoneal cavity.


No single symptom is diagnostic. Patients often complain of dysmenorrhea with pelvic pain, premenstrual dyspareunia, sacral backache during menses, and infertility. Dysuria may indicate involvement of the urinary bladder. Cyclic pelvic pain, usually in the lower abdomen, vagina, posterior pelvis, and back, begins 5 to 7 days before menses, reaches a peak, and lasts 2 to 3 days. Premenstrual tenesmus and diarrhea may indicate lower bowel involvement. Dyspareunia may indicate involvement of the cul-de-sac or ovaries. No correlation exists between the degree of pain and the extent of involvement; many patients are asymptomatic.


Although history and findings of physical examination may suggest endometriosis, and imaging studies (transvaginal ultrasound) may be helpful, definitive diagnosis of endometriosis and staging requires laparoscopy, a procedure that allows direct visualization of ectopic lesions and biopsy.


Medical and surgical approaches may be used to preserve fertility and to increase the woman's potential for achieving pregnancy. Pharmacological management includes the use of hormonal agents to induce endometrial atrophy by maintaining a chronic state of anovulation.

Surgical management includes laparotomy, lysis of adhesions, laparoscopy with laser vaporization of implants, laparotomy with excision of ovarian masses, or total hysterectomy with bilateral salpingo-oophorectomy and removal of aberrant endometrial cysts and implants to encourage fertility. The definitive treatment for endometriosis ends a woman's potential for pregnancy by removal of the uterus, tubes, and ovaries.

Patient care

Providing emotional support and meeting informational needs are major concerns. The patient is encouraged to verbalize feelings and concerns.

The woman is prepared physically and emotionally for any surgical procedure.

Adolescent girls with a narrow vagina or small vaginal meatus are advised to use sanitary napkins rather than tampons to help prevent retrograde flow. Because infertility is a possible complication of endometriosis, a patient who wants children is advised not to postpone childbearing. An annual pelvic examination and Papanicolaou test are recommended.

peritoneal endometriosis

Endometrial tissue found throughout the pelvis.

thoracic endometriosis

Presence of uterine lining in the thorax. Ectopic endometrioses resulting from an ectopic location can cause catamenial hemorrhage or catamenial air leaks.

transplantation endometriosis

Endometriosis occurring within an abdominal incision scar following pelvic surgery.
Medical Dictionary, © 2009 Farlex and Partners


Location at abnormal sites of the glandular and blood-vessel-containing (vascularized) lining tissue of the womb (the ENDOMETRIUM). Endometrial tissue may occur in the Fallopian (uterine) tubes, on the ovaries, within the muscle wall of the womb, anywhere in the pelvis, or even at remoter sites. All endometrial tissue is subject to the hormones that control the menstrual cycle and follows the same sequence of changes that affects the womb lining. Blood produced at these abnormal sites cannot usually escape and there is local pressure and pain with each menstrual period. A large cyst can form in an ovary.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005

Patient discussion about endometriosis

Q. Will my daughter have endometriosis also? I was diagnosed with endometriosis when I was 15. Now, 15 years and many efforts later I finally have an adorable baby girl. Because I had such a bad experience with endometriosis, I'm a little worried- will she have endometriosis too? Is it genetic? Can I do something to prevent it?

A. Your daughter has higher chances to also suffer from endometriosis, but there's really nothing you can do to prevent it, so for the time being you shouldn't really worry about it. What you can do is to be more aware of the appearance of symptoms, so it can be diagnosed more quickly.

Q. Can you get rid of endometriosis?

A. Currently, there is no known cure for endometriosis. Nevertheless, a hysterectomy and/or removal of the ovaries will not guarantee that the endometriosis areas or the symptoms of endometriosis will not come back, since adhesions can be found on other organs besides the reproductive organs. Surgical treatment tends to be conservative, with the goal of addressing pain or infertility issues through removal of the endometriosis tissue without damaging normal tissue. Several medication are known to be helpful occasionally, such as hormones (Progesterone or Progestins),combined oral contraceptive pills, Gonadotropin Releasing Hormone (GnRH) Agonists and more. You should consult your OB/GYN physician about the treatment best suitable for you.

More discussions about endometriosis
This content is provided by iMedix and is subject to iMedix Terms. The Questions and Answers are not endorsed or recommended and are made available by patients, not doctors.
References in periodicals archive ?
average 7.5 years be diagnosed endometriosis "Unfortunately, there is limited data collected consistently on all aspects of endometriosis.
Endometriosis is a chronic disease that deserves early recognition.
A woman may also be put on trial treatment and if symptoms improve, then it would be known to be endometriosis. It may not be the only condition that responds to this type of treatment, but it points you to that direction.
As the time passed, it was cleared that, laparoscopic surgery is not the final solution for all endometriosis patients, and even worse, in some cases induces premature ovarian insufficiency and/or poor response to ART techniques.
An estimated 176 million women (or one in every 10 women worldwide) suffer from endometriosis. Endometriosis is a chronic recurrent disease that has a significant impact on women's health and chances of pregnancy.
In material and methods, Fayer et al described that DNA was extracted from peripheral blood samples of 141 Iranian patients with surgical confirmation of endometriosis and underwent analysis by PCR-RFLP method.
Cesarean section in the first place as well as increased menstrual flow and alcohol consumption have been determined as risk factors for developing endometriosis in many studies, whereas high parity is considered as protective factor.
The author will be joined at the event by Heather Guidone, the Program Director of the Center for Endometriosis Care, for an endometriosis discussion.
Endometriosis is one the most common conditions among women, however, it is one of the least discussed issues worldwide.
Notably, it is proposed that endometriosis may be a potential risk factor for SHiP.[2] Herein, we presented four cases of endometriosis-related SHiP.