Although an estimated 200 million women worldwide and 1 in 10 women in the United States live with endometriosis — a condition where tissue that normally lines the inside of the uterus grow outside a person's uterus — researchers still have lots to learn about this painful obstetric issue. And despite how common endometriosis is, doctors have yet to agree on its exact cause it and how to prevent it.
Perhaps the most puzzling thing about endometriosis is its connection with autoimmune diseases. Although it isn't recognized as one itself, some — but not all — studies show comorbidity between endometriosis and autoimmune diseases like hypothyroidism, lupus, and rheumatoid arthritis.
“Patients with endometriosis are statistically more likely to have allergies and autoimmune diseases compared to women without endometriosis,” says Dr. Andrew Cook, founder and medical director of Vital Health Endometriosis Center. Why that is the case isn’t exactly clear, says Cook. But doctors are now starting to look at endometriosis as an immune system disease in and of itself.
“Patients with endometriosis certainly seem to have some type of immune dysfunction,” says Cook. “It has many similarities with other autoimmune diseases, such as elevated levels of cytokines and other cellular abnormalities.” Endometriosis also shares similar genes, proteins and regulators with other immune diseases.
When looking at the comorbidity of endometriosis and any other disease, it’s important to remember that any two diseases can co-occur by chance — that is to say, there is no proof of causation. For example, 4 percent of the population has type 2 diabetes and has 5 percent has eczema. There is no correlation between the two, but by chance, 0.2 percent of the population have both.
One thing is clear: We need to dig deeper into whether the relationship between endometriosis and autoimmune diseases are a matter of causation and correlation. Until then, anyone with or who suspects they might suffer from endometriosis should regularly see their doctor and both disclose and pointedly ask about any additional health issues.