Are Autoimmune Diseases Actually Becoming More Common?
Yes, several autoimmune diseases are becoming more common, and better detection explains only part of the rise. The useful response isn't a panic panel of blood tests. It's a short list of risks that credibly matter and that you can act on: don't smoke, keep your weight and cardiovascular health in good shape, limit heavy exposures like silica dust and air pollution where you can, and take persistent symptoms and family history seriously.
The rise isn't one thing, and it isn't mainly about turning 50. Three things are happening at once. Doctors find some diseases more often because the tests and the labels got better. Several specific conditions are climbing across countries and age groups. And modern exposures that nudge the immune system, from air pollution to smoking to excess weight, track with higher risk. Which of the three you're looking at decides whether there's anything to do.
Some of the rise is real
The best single snapshot comes from a UK study of more than 22 million people from 2000 to 2019. Roughly one in ten had one of 19 autoimmune diseases across that period. First-ever diagnoses rose only about 4%, so the overall rise was modest. The average also hides the split between diseases. Coeliac disease, Sjögren's syndrome, and Graves' disease showed the largest increases, while Hashimoto's thyroiditis and pernicious anaemia declined modestly. A single environmental switch flipping on after 50 would not produce a split like that.
Some of it is just better looking
Some of the increase is more disease, and some is better detection, and the two are hard to pull apart. In autoimmune hepatitis, applying the simplified diagnostic criteria produced incidence estimates nearly twice as high as the older scoring criteria. Autoimmune encephalitis tripled in one long-studied US county largely because antibody-positive cases were increasingly detected. Billing codes cut both ways too: they can miss real cases and misclassify others. A rising count of diagnoses isn't the same as a clean measure of new disease.
Still, it's not all bookkeeping. In stored US blood samples collected in national surveys and tested with the same method across rounds, better diagnosis in clinic can't explain the antinuclear antibody trend away. A positive antibody is a marker, not a disease. But the same-method trend still points to more underlying autoimmunity.
The main reasons, side by side
| Possible driver | What the evidence shows | What it means for you |
|---|---|---|
| Better diagnosis and coding | New criteria, antibody tests, and coding changes can raise detected case counts without a matching biological change | A higher diagnosis rate alone isn't proof more people are getting sick |
| True increases in specific diseases | Some conditions rose, some fell, and antinuclear antibody prevalence rose in same-method samples | The rise is real enough to take seriously, but it's uneven, not one wave |
| Environmental and occupational exposures | Occupational silica shows a strong, dose-related link in exposed men; air pollution shows consistent but smaller associations | Worth limiting if your work or where you live puts you in the high-exposure group |
| Lifestyle and metabolic risk | Obesity and smoking are consistently tied to higher risk; cardiovascular health tracks lower risk | The most actionable levers, and the ones you already have reasons to fix |
| Infections and immune history | Hospital-treated infections, EBV, and severe COVID-19 are linked to higher risk, while some early infection patterns may protect | No single germ explains the rise; genetics, timing, and severity shape whether infection matters |
What is linked to higher risk
Several of the strongest risks are things you can change. Obesity stands out. A meta-analysis pooling 26 studies tied it to about 40% higher risk of developing an autoimmune disease, with links reported for multiple sclerosis, rheumatoid arthritis, psoriasis, and inflammatory bowel disease, though the pattern isn't uniform across every condition. Fat tissue behaves like an inflammatory organ, one proposed reason. These are associations from observational data, not proof of cause, and the same caveat applies to everything else in this section.
Smoking is the best-established modifiable trigger for seropositive rheumatoid arthritis. Quitting lowers that risk over time, though it can stay modestly elevated for years after you stop. Long-term particulate air pollution shows a consistent but smaller link. Heavy occupational silica dust, the kind some stone and construction workers breathe, was tied to an autoimmune rheumatic disease rate roughly half higher in the most heavily exposed men, rising with cumulative exposure; the link was weaker in women, who were less exposed.
Cardiovascular health ties it together. Among nearly 250,000 UK adults with no prior autoimmune disease, those scoring best on blood pressure, weight, nicotine exposure, sleep, diet, activity, blood lipids, and blood sugar had about a third lower risk of developing one over the next 13 years. The same handful of habits keeps turning up.
Infections belong on the list, though the logic runs both ways. A Danish study of 4.5 million people linked hospital-treated infections to 29 autoimmune diseases, with more infections tied to more risk. Epstein-Barr virus, which most adults carry, is tied to multiple sclerosis, lupus, and others. And a US RECOVER analysis found that, among people infected with SARS-CoV-2, more severe COVID-19 was followed by higher rates of new autoimmune diagnoses than milder infection. But some early-life infection patterns may train the immune system toward tolerance. No single germ explains the rise.
Two popular levers are weaker than the marketing suggests. In the large VITAL trial, fewer autoimmune diagnoses turned up during five years of vitamin D assignment; two years after it ended, the vitamin D effect had faded, while the group assigned marine omega-3 still showed a lower rate of confirmed disease. The 2024 Endocrine Society guideline suggests against routine vitamin D testing in generally healthy adults for prevention, a conditional call resting on low-certainty evidence. The microbiome is an active research line, but the human autoimmune evidence is still mostly observational and inconsistent. That makes broad microbiome testing or supplement stacks a poor use of your attention right now.
What this means for you
None of this supports running a broad autoimmune antibody panel just because the news says these diseases are rising. A positive ANA without symptoms is often not a diagnosis, and ANA positivity is common enough in the general population that broad screening mostly buys you follow-up questions with no clear disease to treat.
What deserves weight is your own situation. In a small ANA-positive at-risk cohort, family history of autoimmune rheumatic disease and one interferon score were the two independent predictors of progression to connective-tissue disease. Autoantibodies can appear years before symptoms, but symptoms still matter: persistent joint swelling, dryness, fatigue paired with other signs, or changing bowel habits deserve real follow-up, especially alongside family history, older age, heavy silica exposure, smoking, or excess weight.
What would change this picture is a study that could cleanly separate better detection from new disease, track exposures before antibodies appear, and test whether cutting those exposures lowers new diagnoses. Until someone does that, the reasonable bet is the one the evidence already supports: the rise is partly more disease and partly better detection, and the risks you can change are the ordinary ones you already had reasons to fix.