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.

© Our Daughters Foundation - All Rights Reserved

Caitlin "My Story"

My Story: Caitlin

August 21, 20253 min read

Caitlin's My Story

I’ve never had “normal” periods. Growing up, I thought it was normal to take ibuprofen around the clock. It wasn’t something we talked about much, so I didn’t know any different.

In high school, I developed gastroparesis, never imagining it could be connected to my periods—especially since my symptoms didn’t look like most patients’. Over the years, I also experienced stabbing pains that were often brushed off as burst cysts.

In my 20s and 30s, I struggled with getting and staying pregnant. Thankfully, I was able to safely deliver two healthy babies, and during that time I had no gastroparesis symptoms at all. But after pregnancy, my periods worsened, and my gastroparesis came roaring back. I sought help from a midwife/nutritionist, multiple OBGYNs, and several dietitians. Despite eating healthy, exercising, and having perfect bloodwork, I kept gaining weight and bloating without explanation. My belly never seemed to match the rest of my body, and for half the month I was completely drained of energy.

In February 2020, I had my first exploratory surgery. The surgeon told me, “There was some growth, but I’d bet money it’s not endo.” The pathology came back positive for endometriosis. I was put into medicinal menopause right as the pandemic shut everything down, and so began a five-year journey: two more excision surgeries, nerve block injections, countless physical therapy sessions. Yet my symptoms kept flaring. I often felt like I was losing my mind—my body was showing clear symptoms, but little could be done to help.

I’m fortunate to have excellent health insurance, because otherwise I could have bought a small second house with what’s been spent on my care. For three years, I was in physical therapy for hip pain and limited mobility—pain my doctor could see during exams, but that never showed up on scans. During my second excision surgery, they found an endo mass, and the pain disappeared afterward (though mobility issues remained).

Working in front of hundreds of people, I constantly worried whether my clothes would still fit by the end of the day due to bloating. I could also tell when I was nearing the need for another excision surgery because I’d break out with painful cystic acne.

Finally, in June 2025, I sought out a new surgeon who specialized in endometriosis. For the first time—other than with my physical therapist—I felt truly heard. She explained the disease in a way that finally made sense. I chose to have a hysterectomy. During surgery, they found one ovary fused to my bladder and endometriosis in multiple places, despite my last excision only eight months earlier. The most shocking part? I had less pain the day after surgery than I did before. Even more surprising, I haven’t had any gastroparesis symptoms since. My surgeon said there’s no research showing a link, but she wasn’t surprised. Sadly, I wasn’t surprised either that research hasn’t been done on these links.

Now, about six weeks post-op, my body is healing, but the emotional scars remain. It’s one thing to choose not to have more children—it’s another to have that choice permanently taken away. I still battle anxiety around food, since my body spent years tying certain meals to painful symptoms. I also fear for my daughter. Anytime she has GI issues, I worry she might inherit this disease.

I’ve been blessed with supportive family and friends, a great workplace, and the financial means to access care. Even with all of that, it still took me 15–20 years from my first symptoms to get a diagnosis.

I share my story in the hope that organizations like Our Daughters Foundation can help change this. By speaking openly about what’s often considered a taboo subject, I want to spare someone else the years of pain I endured.

Endometriosisgastroparesisexcision surgeryDiagnosis Delay
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