Unfortunately, the exact cause of endometriosis is not very clear. Experts have developed many theories, though, which include the following.

Potential Causes of Endometriosis

Retrograde menstruation

During a woman’s period, this theory suggests that the endometrium flows backwards out the Fallopian tubes and into the abdomen instead of forward out of the vagina as it should.

Genetic predisposition

Some women are more susceptible from genetics as older generations pass on the genes to newer generations. Although, this theory still does not give a clear cause of why this condition happens.

Lymphatic or circulatory spread

As endometrium particles have been found before in the eyes and brain, some theorists believe the particles must travel through either the lymphatic system or bloodstream to spread.

Immune dysfunction

Some women may have a weaker immune system that prevents their body from fighting off endometriosis.

Environmental causes

Some research has shown that animals exposed to high levels of the toxin dioxin developed endometriosis. Although, this theory has not been proven for humans.


Metaplasia is a process where one type of cell changes into a different type of cell. This process does happen in the womb, when a person is developing from an embryo. Researchers believe that some people may retain this ability as an adult.

Risk Factors

While any cisgender woman can have endometriosis, many studies have found the following to be common risk factors: 

  • Having a first-degree relative (mother, sister, daughter) with the disease
  • Giving birth for the first time after age 30
  • Race
  • Women with an abnormal uterus


Research has found women of Asian descent to have higher rates than both Black and white women.

Height and Weight

Women with the condition also tend to be taller and thinner.

Menstrual Factors

Menstrual factors for endometriosis include early age at menarche and shorter cycle lengths.


Smoking and risk of endometriosis have an interesting relationship. While smoking typically deteriorates health, it is associated with a decreased risk of endometriosis in some studies. Specifically, exposure to smoke in utero is associated with a decreased risk. However, passive smoking in childhood increases risk.

Other Lifestyle Factors

Other lifestyle factors, including alcohol and caffeine consumption, have also shown an increased risk for endometriosis. Consumption of omega-3 fatty acids conversely are found to result in a decreased risk of endometriosis.


How do you get endometriosis?

Unfortunately, the answer to this question is unknown. Currently, no research shows anything that a woman has done, or has not done, causes it.

Disclaimer: this article does not constitute or replace medical advice. If you have an emergency or a serious medical question, please contact a medical professional or call 911 immediately. To see our full medical disclaimer, visit our Terms of Use page.

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