Autoimmune Surge: Why the Majority of Patients Diagnosed with Autoimmune Diseases are Women

What are Autoimmune Diseases?

Autoimmune diseases are conditions that cause the immune system to mistakenly damage healthy cells in the body because it lacks the ability to differentiate between healthy tissue and potentially harmful antigens. There are more than 100 different autoimmune diseases affecting nearly 10% of the global population. The most common types are type 1 diabetes multiple sclerosis rheumatoid arthritis lupus Crohn’s disease psoriasis and scleroderma. So then what makes this type of disease particularly relevant to women’s health?

Autoimmune Disease in Women

Some studies estimate that 80% of autoimmune patients are women (Angum et al 2020); other more recent research states that women make up 63% of autoimmune diagnoses (Abend et al 2024). The former relied on less accurate methods including studying the prevalence of a single autoimmune disease and using the results to predict the implications for all autoimmune disorders. In contrast the more recent study analyzed data from 105 autoimmune diseases to produce its findings making its results more comprehensive and representative of autoimmune diseases overall.

Either way significantly more women are diagnosed with autoimmune disease than men. Why is that?

“The difference between 80% and 63% is not very large ” Fairweather a researcher on the 2024 study says emphasizing that the primary implications remain unchanged. Far more women have autoimmune diseases than men. In fact 18 out of the 20 most common autoimmune diseases— including rheumatoid arthritis psoriasis autoimmune thyroiditis multiple sclerosis and systemic lupus erythematosus (SLE the most common type of lupus)— are more commonly diagnosed in women than in men.

Why Autoimmune Disease Predominantly Affects Women

Despite decades of research there is yet to be a definitive explanation for the overwhelming female predominance in autoimmune diseases. What we know instead is a convergence of biological mechanisms:

Hormonal Factors: Estrogen is an immune-activating agent. It promotes the production of antibodies and enhances the activity of certain immune cells. Testosterone in contrast tends to suppress immune responses. This fundamental hormonal difference means that women have more reactive immune systems than men. The X Chromosome Hypothesis: A study from Stanford University in 2024 published in Cell identified that a molecule called Xist (produced only in cells with two X chromosomes) can trigger immune responses that resemble autoimmune activity. Researchers found that Xist-associated protein complexes activated immune pathways in female mice and were detected in human autoimmune patients. These complexes were absent in male mice. Although this is still early-stage research this is one of the first mechanistic explanations for the sex-based disparity. Microchimerism: During pregnancy fetal cells cross into the mother’s bloodstream and can persist for decades. These foreign cells carrying the father’s genetic material may trigger certain immune responses in some women. Women with scleroderma and thyroiditis have been found to have higher levels of microchimerism. It does not explain autoimmune disease in women who have never been pregnant but it may be a contributing factor in a subset of cases.

There is no single explanation that fully accounts for the differences in the occurrence of autoimmune disease in men and women. However current research suggests that this dichotomy arises from a combination of genetic predisposition hormonal influences and environmental triggers such as infections or toxin exposure and stochastic factors that remain unidentified.

The Struggles of Women Diagnosed with Autoimmune Disease

Behind these clinical and biological mechanisms shifting percentages lie the real lived experiences of millions of women fighting the invisible war.

An article by Organon shows the reality of autoimmune disease. This article demonstrates how a woman’s life can change after struggling with symptoms and months of undiagnosed pain.

“She was 39 newly promoted and had just welcomed her second child when the fatigue hit. Then came the joint pain the swelling and the uncertainty. It took months—and multiple specialists—before she was diagnosed with rheumatoid arthritis a chronic inflammatory disease that can immobilize fingers wrists feet and ankle joints.”

Another article by Autoimmune Association emphasized the unfortunately shared struggle that many women face: not being believed by the medical system.

For seven whole years Erika lived in a body that was betraying her and a world that dismissed her symptoms. She was told she needed more sleep more water fewer stressors and every other reason in the book.

Finally in 2017 Erika was diagnosed with multiple autoimmune diseases: lupus Sjögren’s rheumatoid arthritis (RA) Hashimoto’s disease pernicious anemia and autoimmune dysautonomia. Her pain was finally acknowledged but that validation also came with fear.

“It was overwhelming ” Erika admitted. “Finally understanding why I felt the way I did didn’t make it easier. It just made it real.”

Like millions of women around the world their stories are not uncommon– but they are often unheard.