Endometriosis – causes, symptoms and other associated risk factors


Endometriosis in many cases is a painful disorder. In this condition the tissue which normally lines the inside of the uterus (which is known as endometrium) grows outside the uterus. This condition most commonly involves the ovaries, fallopian tubes and the tissue lining the pelvis. There are rare cases when the endometrial tissue can spread beyond pelvic organs. When some women have the endometriosis (which is the displaced endometrial tissue), then it continues to act as it normally would it thickens, breaks down and bleeds with each menstrual cycle. This displaced tissue has no way to exit the body and this is a reason why it becomes trapped. When the endometriosis involves the ovaries, then the cysts may form (they are called endometriomas). The surrounding tissue can become irritated and it will eventually develop scar tissue and adhesions – abnormal bands of fibrous tissue which can cause pelvic tissues and organs to stick each other. This condition can cause pain especially during the period. In some cases it can be severe pain. Also the fertility problem can develop [1]. But there are effective treatments which can help for treating endometriosis.

Symptoms of endometriosis

The pelvic pain is the primary symptom of endometriosis and it is often associated with the menstrual period. There are many women who experience cramping during the menstrual period but women who suffer from endometriosis are describing that their menstrual pain is far worse than the usual pain [2]. Also they have reported that the pain increases over time. Here are the most common signs and symptoms of endometriosis:

  • Infertility: This condition is first diagnosed in some women who are seeking treatment for infertility [1].
  • Excessive bleeding: You can experience bleeding between periods (menometrorrhagia) or occasional heavy periods (menorrhagia). [3]
  • Pain with bowel movements or urination: You are most likely to experience these symptoms during your period. [4]
  • Pain with intercourse: Pain during sex or after it is very common symptom of endometriosis.
  • Painful periods (dysmenorrhea): Cramping and pelvic pain can begin before your period and they will extend several days into your periods. Also you can have abdominal pain and lower back pain. [2]
  • Other symptoms: Also you can experience constipation, diarrhea, fatigue, bloating or nausea, especially during menstrual periods.

Endometriosis - causes, symptoms and other associated risk factorsEndometriosis causes and risk factors

The severity of the pain that you have is not necessarily a reliable indicator of the extent of this condition. There are some women who have mild endometriosis and they have intense pain while other women who have advanced endometriosis can have little pain or even not pain at all. There are some cases when endometriosis is mistaken for other conditions which can cause pelvic pain such as ovarian cysts or PID (pelvic inflammatory disease). Also this condition in some cases can be confused with IBS (irritable bowel syndrome) which is a condition that causes bouts of abdominal cramping, constipation and diarrhea. Irritable bowel syndrome can be accompanied with endometriosis which can complicate the condition.

Causes: The exact cause for endometriosis is not known but there are some possible explanations such as:

  • Immune system disorder: It is possible that a problem with the immune system can make the body unable to recognize and destroy the endometrial tissue which is growing outside the uterus. [5]
  • Retrograde menstruation: In this type of menstruation, the menstrual blood which has endometrial cells flow back through the fallopian tubes and into the pelvic cavity instead of out of the body. They (displaced endometrial cells) stick to the pelvic walls and surfaces of the pelvic organs. There they grow and continue to thicken and bleed over the course of each menstrual cycle.
  • Endometrial cell transport: We know that the blood vessels or the tissue fluid (lymphatic) system may transport endometrial cells to other parts of the body.
  • Transformation of peritoneal cells: There is something which is known as the “induction theory”, experts propose that hormones or immune factors promote transformation of peritoneal cells – cells that line the inner side of your abdomen – into the endometrial cells. [6]


[1] Bulletti C, Coccia ME, Battistoni S, Borini A. Endometriosis and infertility. Journal of Assisted Reproduction and Genetics. 2010;27(8):441–7.

[2] Bloski T, Pierson R. Endometriosis and chronic pelvic pain: Unraveling the mystery behind this complex condition. Nursing for Women’s Health. 2008;12(5):382–95.

[3] The ESHRE Capri Workshop Group. Endometrial bleeding. Human Reproduction Update. 2007;13(5):421-31.

[4] Charatsi D, Koukoura O, Ntavela IG, et al. Gastrointestinal and urinary tract endometriosis: A review on the commonest locations of extrapelvic endometriosis. Advances in Medicine. 2018.

[5] Shigesi N, Kvaskoff M, Kirtley S, et al. The association between endometriosis and autoimmune diseases: a systematic review and meta-analysis. Human Reproduction Update. 2019;25(4):486-503.

[6] van der Linden PJQ. Theories on the pathogenesis of endometriosis. Human Reproduction Volume. 1996;11(Suppl3):53-65.


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