Many studies link endometriosis to other conditions that often exist in the same patient at the same time, commonly known as comorbidities. These comorbidities may occur because they have mechanisms similar to that of endometriosis, or because they share the same risk factors.

The most common comorbidities of endometriosis include the following:

• Mental health conditions
• Cancer
• Fibromyalgia
• Autoimmune disorders

The mental health conditions most often associated with endometriosis include anxiety disorders and depression, although they also include any disorder that affects a person’s behavior, feelings, and thoughts. Anxiety disorders occur when normal anxious feelings grow to the point that they negatively impact daily activities and functioning. Depression is similar to normal feelings of sadness, except it’s more intense and doesn’t go away. It prevents a person from enjoying the activities they once did and also reduces feelings of self-esteem and self-worth.

Experts are currently studying the correlation between endometriosis and mental health conditions. Several recent studies show that the symptoms and experiences related to endometriosis lead to a decreased quality of life, resulting in anxiety and depression. This outcome is especially likely without an understanding partner and other sources of social support. Women who suffer from chronic and severe symptoms of endometriosis are also more likely to experience a loss of mental health.

The link between endometriosis and various forms of cancer has been under close scrutiny for decades, although more work is needed to adequately understand this relationship. The direct progression of endometrial lesions into cancer is quite rare, as it only occurs in about one percent of cases. Of these cases, about 80 percent progress into ovarian cancer. The most common theory for this process is that atypical lesions are composed of cells with a genetic propensity for cancer.

In addition to the direct transformation into cancer, endometriosis may create conditions favorable for cancer to develop or share risk factors for certain types of cancer. In addition to ovarian cancer, the cancer is most closely associated with endometriosis include endometrial cancer, colorectal cancer and non-Hodgkin lymphoma. Further study is needed to determine if these cancers are a cause or result of endometriosis.

fibromyalgia is a medical condition characterized by widespread pain throughout the musculoskeletal system. This pain is constant, and feels like a dull ache, both above and below the waist. In the latter case, the pain of fibromyalgia is often confused for that of endometriosis. While the link between the two conditions isn’t well understood, many studies show that women with endometriosis are more likely to suffer from fibromyalgia. One possible reason for this connection is that endometriosis is a precursor for fibromyalgia.

An altered immune system is one of the possible explanations for endometrial tissue growing outside the uterus, which is the cause of endometriosis. Researchers have therefore proposed a link between autoimmune conditions and endometriosis. The autoimmune conditions most closely associated with endometriosis include multiple sclerosis, rheumatoid arthritis, and inflammatory bowel disease.

For more information, please visit our complete Endometriosis Guide.