Endometriosis is a painful female reproductive condition associated with chronic menstrual pain and infertility. Endometriosis affects nearly six to ten percent of women worldwide, and only began to gain recognition from the medical community in the late nineties.1

What is Endometriosis?

Endometriosis occurs when the endometrium—tissue that typically lines the walls of the uterus—grows elsewhere in the body. The endometrial tissue may spread to the ovaries, fallopian tubes, pelvic tissue, and, very rarely, past pelvic organs.  In a normal menstrual cycle,  a complex system of hormones causes the endometrium to thicken, break down, and exit the uterus in the form of menstrual blood. Endometrial tissue that is displaced due to endometriosis follows the same life cycle; however, with no way to leave the body, the trapped tissue coagulates. This can result in the formation of cysts called endometriomas, which may later cause the development of painful and sticky scar tissue. Often, the scar tissue adheres to itself causing other pelvic tissues and organs to stick to each other, resulting in severe pain and cramping. 1


While the exact etiology of endometriosis remains uncertain, there are a number of possible causes:

  1.  Retrograde menstruation occurs when some of the endometrial discharge, released during a female’s menstrual period, does not follow the normal pathway out of the vagina; rather, it travels backward, up the oviducts. These pieces of endometrial tissue become stuck within the pelvic cavity and settle onto irregular places outside of the uterus.1 While researchers previously thought that this was the most probable cause for endometriosis, new data shows that while 90% of females experience retrograde menstruation, only 10% actually have endometriosis.3

  2. Genetics may play a role in endometriosis. Research shows that “females who have a close female relative with endometriosis are five to seven times more likely to have it themselves.” 3

  3. The induction theory proposes that certain hormones and immune factors may promote the transformation of cells that line that the abdomen (peritoneal cells) into endometrial tissue cells.

  4. A faulty immune response may also impede the ability of the body’s immune cells to target displaced endometrial tissue, thus resulting in tissue buildup outside of the uterus.1

While the medical community is still unsure about what exactly causes endometriosis, most agree that both genetic and environmental factors play a role.

Risk Factors

Research shows that there are a number of risk factors, many of which arise during puberty, that may increase an individual’s likelihood of developing endometriosis.

  1. Early menstruation can increase the risk of endometriosis. On average, females begin to menstruate around 12 years old. While most females will start their period within the range of 10-15 years old, having a menstrual cycle much earlier than this can indicate abnormal reproductive function.

  2. Later menstruation is also a risk factor for endometriosis. Very late menstrual periods are often a result of abnormal hormone levels, which, in turn, increase the risk of problematic reproductive function.

  3. Short menstrual cycles, specifically those that are shorter than 27 days, are often a strong risk factor.

  4. Low BMI can affect the regularity and general function of the menstrual cycle, which often throw the body’s hormones out of balance.

  5. Lastly, genetic predisposition has a strong influence. Research shows a six-fold increased incidence in females with an affected first-degree relative (such as a mother, aunt, or sister).1

Scientists cannot conclusively point to one single risk factor, but rather have found that combinations of these issues are typically responsible for the onset of endometriosis.


Symptoms of endometriosis include severe, long-term pelvic pain, abnormal vaginal bleeding, and infertility. Some females may have no symptoms at all.

  1. Pelvic pain, often called “killer cramps,” can be relentless, and typical over the counter pain relief medications tend to be insufficient.3

  2. Abnormal bleeding is another possible sign of endometriosis.1 Females may experience heavy periods or experience spotting in between periods. Some may bleed after sex or have blood in their stool. However, abnormal bleeding does not always mean a female has endometriosis. Bleeding patterns vary greatly between individuals, and should be judged as irregular only compared to that individual’s baseline.

  3. ​Infertility, or the inability to get pregnant, can be a sign of endometriosis. About 40% of infertile females have endometriosis.1 Many go without noticing or diagnosing their endometriosis and only become aware of the condition once they find difficulties in becoming pregnant or have other health-related problems. Having endometriosis does not necessarily mean a female cannot have children, but it may be more difficult for her to conceive. The more severe the endometriosis, the more difficult it may be to become pregnant. Individuals with moderate to severe cases can also become pregnant, but may need to have surgery, assisted reproductive technologies, or both.

  4. Long periods that last more than seven days, or any abnormality in the menstrual cycle, can be a symptom of endometriosis.3 Any abnormality in the menstrual cycle can often be a symptom of endometriosis.

  5. Individuals may also experience pain during sex, if endometrial tissue grows in the lower parts of the uterus or behind the vagina. This could affect uterine nerves and ligaments, causing pain when the growths are agitated by the movements of sex. This pain may subside immediately after sex, or in more severe cases, last for a few days after intercourse.3

  6. Digestive issues such as nausea, constipation, and gastritis often occur in very severe cases, when the endometrial tissue invades the intestinal wall.3

Endometriosis can have a wide range of symptoms. Some individuals experience debilitating, chronic pain, while others may go most of their life without knowing they have the condition.


On average, it takes ten years to diagnose endometriosis from the initial onset of symptoms. This is often due to the high rates of misdiagnosis, as well as a general lack of information in both the medical community and public. Endometriosis cannot be detected with a CT, MRI, or ultrasound. The only surefire way to diagnose the condition is through a diagnostic laparoscopy, an invasive procedure that can take a toll on the patient. A laparoscopy is a surgical procedure where a small viewing tube with a camera , known as a laparascope, is inserted through an incision in the abdomen. This allows doctors to clearly see the inner organs, and based on the presence of endometrial tissue, make a diagnosis. 3


Currently, the most effective treatment for endometriosis is laparoscopic excision surgery, where the surgeon excises lesions or cysts. This surgery removes endometrial tissue that is lodged on and in different areas of the pelvic organs. Additionally, endometrial tissue can be addressed with ablation or cauterization; however, this method is only used for less severe cases as it is a short-term remedy.3

Although hysterectomies used to be standard medical procedure when treating endometriosis, recent information indicates that it is rarely the most effective treatment. Since most cysts and lesions grow on areas around the reproductive  organs, removing the uterus will have little to no effect.3 Other options to treat endometriosis include extended/continuous cycle birth control or an IUD (if an individual is not trying to get pregnant), or a prescription gonadotropin-releasing hormone (GnRH) agonist (if an individual is trying to get pregnant). This medication works by binding to gonadotropic hormone receptors, so that the actual hormone is blocked from the receptor. This inhibits ovulation and the growth of endometrial tissue.2

Support for Women with Endometriosis

Endometriosis is a common and often very painful condition for females. The following is  the home page for the National Endometriosis Foundation of America: www.endofound.org.

This website offers resources such as fact sheets about endometriosis, toolkits on pain management, support groups, and much more. With a strong support system, comprehensive medical care, and healthy lifestyle choices, people with endometriosis can manage their condition and maintain a high quality of life.


Endometriosis is a chronic condition that affects millions every year. Although research on causes and risk factors has been relatively inconclusive, modern medicine has made it possible to live happily and healthily, in spite of endometriosis.



  1. “Endometriosis." Mayo Clinic. Mayo Foundation for Medical Education and Research, 20 Aug. 2016. Web.
  2. "Endometriosis." Womenshealth.gov. N.p., 10 July 2017. Web.
  3. "What Is Endometriosis? Causes, Symptoms and Treatments." Endometriosis Foundation of America. N.p., 04 Apr. 2017. Web.

Last Updated: 13 January 2018.