Is Fibromyalgia an Autoimmune Disease?
It's one of the most searched questions about fibromyalgia, and the short answer is no: fibromyalgia isn't classed as an autoimmune disease. The longer answer is more interesting, because research over the last few years suggests the immune system may play a part for some people.
Why it isn't classed as autoimmune
In autoimmune diseases such as rheumatoid arthritis, lupus or Sjögren's, the immune system attacks the body's own tissues. That usually leaves evidence: specific antibodies in the blood, inflammation, and damage to joints or organs that tests and scans can find. Fibromyalgia doesn't show that pattern. Blood tests and scans are typically normal, and there's no tissue damage to explain the pain.
Instead, fibromyalgia is understood mainly as a problem with how the nervous system processes pain, known as central sensitisation. Pain specialists now use the term nociplastic pain for this: real pain that comes from changes in pain processing rather than from damage or inflammation.
Why people often think it is
- The symptoms overlap. Widespread pain, fatigue, brain fog and stiffness also happen in lupus, rheumatoid arthritis and Sjögren's, which is why doctors usually test for these first.
- They often happen together. Fibromyalgia is much more common in people with autoimmune diseases. Studies suggest around one in five people with rheumatoid arthritis or lupus also has fibromyalgia.
- Borderline blood tests. A weakly positive ANA test is common in the general population and can cause confusion, even when there's no autoimmune disease.
Where the research is heading
Two lines of research have reopened the question. In 2021, a study led by Andreas Goebel and colleagues found that antibodies taken from people with fibromyalgia, injected into mice, made the mice more sensitive to pain, suggesting the immune system might drive the pain in at least some cases. Separately, several studies have found damage to small nerve fibres in the skin of a large share of people with fibromyalgia. Neither finding has changed how fibromyalgia is diagnosed or treated yet, but they suggest it may not be a single condition with a single cause.
What this means for you
If you have fibromyalgia symptoms, it's reasonable to ask whether autoimmune conditions have been ruled out, especially if you have signs like swollen joints, rashes, dry eyes and mouth, or raised inflammation markers. Fibromyalgia and an autoimmune disease can exist together, and one doesn't rule out the other. And if your tests are normal, that doesn't mean the pain isn't real. It means it's coming from how pain is processed, which is exactly what fibromyalgia is.
Track what fibromyalgia is actually doing
Fibro logs pain, fatigue, sleep, brain fog and flares alongside barometric pressure, so you and your doctor can see patterns instead of guessing.
This article is for general information and isn't a substitute for medical advice. Talk to a doctor about your own symptoms, tests and treatment.