What is Endometriosis? – Symptoms and Treatments

What is Endometriosis?

Endometriosis is a well known and often painful, gynaecological condition, which derives from the word endometrium (which describes the tissue lining the uterus). It affects an estimated 2% to 10% of women of childbearing age [1]. Endometrial tissue comprises: connective tissue, blood cells and glands. Generally speaking, this form of tissue grows in the uterus in order to ready the lining of the womb for ovulation.

“With endometriosis, the endometrial-like tissue acts as endometrial tissue would — it thickens, breaks down & bleeds with each menstrual cycle. But because this tissue has no way to exit your body, it becomes trapped” [2]

This tissue in the uterus builds up, and if a woman has not become pregnant, sheds away, during the course of the menstrual cycle. Individuals with endometriosis develop tissue which acts and looks the same as the endometrial tissue which is found outside the uterus [1]. This is normally on the tissue lining the pelvis, the fallopian tubes, or the ovaries. In rare instances, endometrial tissue can extend beyond the pelvic organs [2].

The misplaced tissue responds to the hormonal fluctuations of the menstrual cycle by building up and breaking down every month, just as the endometrium does. This generates a small amount of bleeding within the pelvis, thus leading to adhesions (scarring), swelling, and inflammation of the normal tissue which encircles the endometriosis implants. If the ovary is part of this scenario, a blood blister encircled by a endometrioma (fibrous cyst), can form. This is due to blood becoming embedded in the normal ovarian tissue [1]. Note: adhesions refer to normal bands of fibrous tissue which can make pelvic organs and tissues stick to each other [2].

“Endometriosis can cause pain — sometimes severe — especially during menstrual periods. Fertility problems also may develop. Fortunately, effective treatments are available” [2]

So What Are the Main Symptoms of Endometriosis?

The main symptom is pelvic pain, which is frequently linked to menstrual periods. It is however, important to note that while a large percentage of women suffer from intermittent cramps at the time of their period, in most cases, those who have endometriosis state that their menstrual pain is substantially worse than usual. In addition, the pain can become more intense as time goes on [2]. Other symptoms comprise:

•Dysmenorrhea (painful periods). Of note, cramping and pain in the pelvis could start prior to, and continue for a few days into a menstrual period. Abdominal pain and back pain may also occur
•Painful intercourse. Women suffering from endometriosis are very inclined to experience pain at the time of, or after having sex
•Painful urination or bowel movements, which of which occur during menstrual periods
•Episodic heavy intermenstrual bleeding (bleeding in between periods), or during menstrual periods
•Issues with fertility. On some occasions, endometriosis is diagnosed for the first time when a woman is searching for infertility treatment
•Nausea or bloating, constipation, diarrhoea or fatigue, particularly at the time of menstrual periods [2].


It is very important to understand that the degree of pain that you may experience, does not necessarily represent the extent of the condition. For example, it is possible to have advanced endometriosis, yet feel zero or little pain. Or conversely, to have mild endometriosis and experience severe pain [2].

Can Endometriosis Be Mistaken for Other Pelvic Pain Conditions?

The answer to this is a definite yes: other conditions which can produce pelvic pain, i.e. ovarian cysts or PID (pelvic inflammatory disease), could be confused with IBS (irritable bowel syndrome), as they generate bouts of abdominal cramping, constipation and diarrhoea. Of note: irritable bowel syndrome can be present at the same time as endometriosis, thus an endometriosis diagnosis may be easily overlooked by a medic who is not a specialist in the field of endometriosis [2].

So What Are the Causes of Endometriosis?

At the present time, the precise cause of endometriosis has not yet been fully established [2], and more research is needed. However possible explanations include:

•Regressive menstruation. In this case: instead of flowing out of the body, menstrual blood (which comprises endometrial cells), flows back into the pelvic cavity via the fallopian tubes. This causes the endometrial cells to stick on to pelvic organ surfaces and pelvic walls. Once there, during each menstrual cycle, they expand, continue to bleed, and become thicker [2].
•Transformation of the peritoneal cells (which line the inner side of the abdomen) into endometrial-like cells. Coined the “induction theory,” scientists have put forward the possibility that immune factors or hormones encourage this transformation [2].
•The formation of surgical scars. Endometrial cells can bind to a surgical incision post-C-section, post-hysterectomy, or after other types of surgery [2].
•Endometrial cell transport. The lymphatic system (tissue fluid), or blood vessels, could carry endometrial cells to other regions of the body [2].
•Transformation of embryonic cells. At the time of puberty, oestrogen and other hormones could change embryonic cells (cells at the earliest phase of evolution), into endometrial-like cell implants [2].
•Disorders affecting the immune system. The body may not be able to acknowledge and kill off endometrial-like tissue growing outside the uterus, if the immune system is not optimal [2].

What Are the Risk Factors of Endometriosis?

There are a number of elements which render some women at higher risk of developing endometriosis [2]. These include:

•Not having given birth
•Shortened menstrual cycles of under 27 days
•Heavy menstrual periods which continue for over 7 days
•Menstruating from an early age
•Going through menopause at a more advanced age
•Having a higher lifetime exposure to the oestrogen generated by the body
•Experiencing higher levels of oestrogen within the body
•Having a low BMI (body mass index)
•Medical issues which obstruct menstrual flow leaving the body
•Abnormalities of the reproductive tract
•One or more relatives (sister, mother or aunt) who have, or had, endometriosis [2].

Of note: “people with endometriosis may be more likely to have a close relative with the disease. However, research into the potential link is still developing [3].

When Does Endometriosis Develop?

Generally speaking, this condition arises several years after the start of menarche (menstruation). Symptoms and signs of endometriosis could be temporarily ameliorated if you become pregnant; and unless you are taking oestrogen, they could vanish altogether at menopause [2].


[1]. John Hopkins Medicine (2020). “Endometriosis.”

[2]. Mayo Clinic (2019). “Endometriosis.”

[3]. Medical News Today (2020). “Is endometriosis hereditary? What to know.”
HYPERLINK “https://www.medicalnewstoday.com/articles/is-endometriosis-hereditary” \