Are Endometriosis, Adenomyosis, and PCOS Autoimmune Conditions?
By Our Daughters Foundation
More and more women are asking an important question: Could my hormone-related illness also be connected to my immune system?
Conditions like endometriosis, adenomyosis, and polycystic ovary syndrome (PCOS) are often discussed in the context of reproductive health or hormonal imbalance. But researchers are beginning to explore deeper connections—specifically, whether autoimmunity plays a role in these diseases.
Let’s break down what the science says—and what questions remain unanswered.
Are Endometriosis, Adenomyosis, and PCOS Autoimmune Conditions?
By Our Daughters Foundation
More and more women are asking an important question: Could my hormone-related illness also be connected to my immune system?
Conditions like endometriosis, adenomyosis, and polycystic ovary syndrome (PCOS) are often discussed in the context of reproductive health or hormonal imbalance. But researchers are beginning to explore deeper connections—specifically, whether autoimmunity plays a role in these diseases.
Let’s break down what the science says—and what questions remain unanswered.
What Is Autoimmunity?
The immune system is designed to protect the body from threats like viruses and bacteria. But in autoimmune diseases, the immune system becomes misguided and starts attacking the body’s own cells and tissues.
Common autoimmune conditions include:
• Lupus
• Rheumatoid arthritis
• Hashimoto’s thyroiditis
• Multiple sclerosis
Symptoms vary widely, but many autoimmune conditions involve chronic inflammation, pain, fatigue, and a pattern of flare-ups.
The Immune System and Endometriosis
Endometriosis occurs when tissue similar to the uterine lining grows outside the uterus—causing pain, inflammation, and sometimes infertility. While its exact cause is still debated, many researchers believe that the immune system fails to clear out these rogue cells effectively.
Several studies have found:
• Women with endometriosis often have higher levels of inflammatory markers, like cytokines and prostaglandins.
• Natural killer (NK) cell activity is lower in women with endometriosis, impairing the immune system’s ability to destroy misplaced cells.
• There are elevated autoantibodies in some patients, suggesting an autoimmune component.
Some scientists now consider endometriosis to be a non-classical autoimmune disease—showing many features of one without meeting all diagnostic criteria.
Further reading:
• NIH - Immune dysfunction in endometriosis: https://pubmed.ncbi.nlm.nih.gov/30664929/
• Cleveland Clinic - Endometriosis and the Immune System: https://health.clevelandclinic.org/endometriosis-and-the-immune-system/
What About Adenomyosis?
Adenomyosis is sometimes called the "sister disease" of endometriosis. It occurs when endometrial tissue grows into the muscular wall of the uterus. It's less studied, but immune abnormalities have also been observed.
Research is still emerging, but here’s what we know:
• Women with adenomyosis show immune cell changes and chronic inflammation within the uterus.
• Some studies report increased macrophage and mast cell activity—cells involved in both immune defense and inflammation
• The condition often coexists with endometriosis, raising questions about shared immune pathways.
While it’s too early to label adenomyosis an autoimmune disorder, it may involve an immune imbalance that contributes to symptoms.
Further reading:
• Frontiers in Immunology - Immunopathogenesis of Adenomyosis: https://www.frontiersin.org/articles/10.3389/fimmu.2021.796273/full
PCOS and Autoimmune Overlap
Polycystic ovary syndrome (PCOS) is primarily known as a hormonal disorder involving androgen excess and insulin resistance. However, there’s growing interest in its immune connections, especially in women with chronic inflammation or thyroid issues.
Emerging links include:
• Hashimoto’s thyroiditis (an autoimmune thyroid disorder) is more common in women with PCOS.
• Inflammatory markers like C-reactive protein (CRP) are often elevated in PCOS patients.
• Some PCOS patients have anti-ovarian antibodies, suggesting potential autoimmunity.
Still, the autoimmune theory is more speculative in PCOS than in endometriosis.
Further reading:
Further reading:
• Journal of Clinical Endocrinology & Metabolism - PCOS and Autoimmune Disease: https://academic.oup.com/jcem/article/106/9/e3536/6280755
Why Does This Matter?
If immune dysfunction is part of the puzzle, treatment strategies may need to shift. Many women with endometriosis, adenomyosis, or PCOS are treated solely with hormone suppression—but if autoimmunity is involved, we may also need to address inflammation, gut health, and immune regulation.
There’s also hope that newer treatments—like immunomodulatory therapies or even personalized nutrition and lifestyle interventions—could improve outcomes when tailored to the immune system’s role.
Bottom Line
We don’t yet have all the answers, but the research is evolving. Endometriosis, adenomyosis, and PCOS may not be traditional autoimmune diseases—but they often coexist with immune dysfunction, and the overlap deserves attention. At Our Daughters Foundation, we believe in honoring women’s voices, advocating for deeper research, and pursuing whole-body solutions.
If you’ve experienced overlapping conditions like endo, thyroid disease, or unexplained inflammation—you’re not alone.
What Is Autoimmunity?
The immune system is designed to protect the body from threats like viruses and bacteria. But in autoimmune diseases, the immune system becomes misguided and starts attacking the body’s own cells and tissues.
Common autoimmune conditions include:
• Lupus
• Rheumatoid arthritis
• Hashimoto’s thyroiditis
• Multiple sclerosis
Symptoms vary widely, but many autoimmune conditions involve chronic inflammation, pain, fatigue, and a pattern of flare-ups.
The Immune System and Endometriosis
Endometriosis occurs when tissue similar to the uterine lining grows outside the uterus—causing pain, inflammation, and sometimes infertility. While its exact cause is still debated, many researchers believe that the immune system fails to clear out these rogue cells effectively.
Several studies have found:
• Women with endometriosis often have higher levels of inflammatory markers, like cytokines and prostaglandins.
• Natural killer (NK) cell activity is lower in women with endometriosis, impairing the immune system’s ability to destroy misplaced cells.
• There are elevated autoantibodies in some patients, suggesting an autoimmune component.
Some scientists now consider endometriosis to be a non-classical autoimmune disease—showing many features of one without meeting all diagnostic criteria.
Further reading:
• NIH - Immune dysfunction in endometriosis: https://pubmed.ncbi.nlm.nih.gov/30664929/
• Cleveland Clinic - Endometriosis and the Immune System: https://health.clevelandclinic.org/endometriosis-and-the-immune-system/
What About Adenomyosis?
Adenomyosis is sometimes called the "sister disease" of endometriosis. It occurs when endometrial tissue grows into the muscular wall of the uterus. It's less studied, but immune abnormalities have also been observed.
Research is still emerging, but here’s what we know:
• Women with adenomyosis show immune cell changes and chronic inflammation within the uterus.
• Some studies report increased macrophage and mast cell activity—cells involved in both immune defense and inflammation
• The condition often coexists with endometriosis, raising questions about shared immune pathways.
While it’s too early to label adenomyosis an autoimmune disorder, it may involve an immune imbalance that contributes to symptoms.
Further reading:
• Frontiers in Immunology - Immunopathogenesis of Adenomyosis: https://www.frontiersin.org/articles/10.3389/fimmu.2021.796273/full
PCOS and Autoimmune Overlap
Polycystic ovary syndrome (PCOS) is primarily known as a hormonal disorder involving androgen excess and insulin resistance. However, there’s growing interest in its immune connections, especially in women with chronic inflammation or thyroid issues.
Emerging links include:
• Hashimoto’s thyroiditis (an autoimmune thyroid disorder) is more common in women with PCOS.
• Inflammatory markers like C-reactive protein (CRP) are often elevated in PCOS patients.
• Some PCOS patients have anti-ovarian antibodies, suggesting potential autoimmunity.
Still, the autoimmune theory is more speculative in PCOS than in endometriosis.
Further reading:
Further reading:
• Journal of Clinical Endocrinology & Metabolism - PCOS and Autoimmune Disease: https://academic.oup.com/jcem/article/106/9/e3536/6280755
Why Does This Matter?
If immune dysfunction is part of the puzzle, treatment strategies may need to shift. Many women with endometriosis, adenomyosis, or PCOS are treated solely with hormone suppression—but if autoimmunity is involved, we may also need to address inflammation, gut health, and immune regulation.
There’s also hope that newer treatments—like immunomodulatory therapies or even personalized nutrition and lifestyle interventions—could improve outcomes when tailored to the immune system’s role.
Bottom Line
We don’t yet have all the answers, but the research is evolving. Endometriosis, adenomyosis, and PCOS may not be traditional autoimmune diseases—but they often coexist with immune dysfunction, and the overlap deserves attention. At Our Daughters Foundation, we believe in honoring women’s voices, advocating for deeper research, and pursuing whole-body solutions.
If you’ve experienced overlapping conditions like endo, thyroid disease, or unexplained inflammation—you’re not alone.
Join Us: Make a Difference Today
Your support can transform lives. Every donation helps us fund research, advocate for better care, and provide essential grants to women facing debilitating conditions.
Join Us: Make a Difference Today
Your support can transform lives. Every donation helps us fund research, advocate for better care, and provide essential grants to women facing debilitating conditions.
Endometriosis: A Cancer-Mimicking Disease
A recent article published in the Annals of Research in Oncology (Vol. 5 June 2025) looks at the similarities between the behavior of some cancers and endometriosis. The article states, "Endometriosis, defined by the presence of endometrial-like tissue beyond the uterine cavity, afflicts over 190 million young women worldwide and often significantly reduces quality of life. Despite being historically classified as a benign gynecologic disorder, endometriosis can mimic cancer in imaging findings, serum tumor markers, and molecular signature." The article urges a different approach to the disease due to the fact that the current approach takes so long to diagnose (8-10 years on average) and leads many women down the path of repeated surgeries and hormone therapy that does little to treat the disease. The impact statement of the article urges a different approach altogether, "This perspective advocates a structured translational approach, integrating meticulous preclinical validation, phase-appropriate clinical trials, and rigorous safeguards in artificial intelligence and biomarker development, to bridge critical gaps in understanding disease biology."
We have summarized the points of the article below and also put the link to the full article. We fully believe that it is time for a different approach and are looking for opportunities to support research that is happening in the study of Endometriosis. Please join us in raising awareness and making some noise on the topic.
Summary of Article (in an oversimplified manner):
Why Endometriosis Acts Like Cancer
It spreads like cancer.
It can grow into nearby organs and even travel around the body—just like cancer does. It invades nearby tissue and can spread to just about any place in the body including the brain, the tissue in your legs, lymph nodes...they have found it just about everywhere.
It tricks doctors.
On scans and in lab tests, it looks just like cancer, so people sometimes get misdiagnosed. Even trickier, more often than not, Endometriosis lesions are not detectable on imaging which means that a diagnostic laparoscopic surgery is needed for diagnosis. Imagine how long that prolongs diagnosis and how often the diagnostic surgery is not covered by insurance. Even worse, how often women are told that "all is normal" because nothing was detected on imaging.
It won’t stop growing.
The tissue doesn’t follow normal rules—it keeps growing even when it’s not supposed to. Healthy cells know when to stop growing. Endometriosis doesn't. It uses the same tricks that cancer cells do to stay alive and keep growing.
It builds its own blood supply.
Like cancer, it tells the body to grow new blood vessels to feed it. The article gets into more specifics by explaining that endometriosis uses high levels of VEGF, MIF, and prostaglandins to build blood vessels - a hallmark of tumor growth.
It hides from the immune system.
It finds ways to stay safe, so the body doesn’t attack it—just like some cancer cells.
It has messed-up signals.
Inside the cells, the “messages” that tell cells when to grow or die are broken. These are the same bad messages found in cancer cells.
What These Doctors Are Saying:
Endometriosis has many of the same cell problems that cancer does.
Some women with endometriosis have a higher risk of getting a certain kind of ovarian cancer.
Doctors think we should study and treat it more like cancer, using:
Special medicines that stop growth
Tests to find it earlier
Research on how to stop it from coming back
