Are we any closer to understanding the cause of Fibromyalgia?

If you live with fibromyalgia, you’ve almost certainly asked this question, probably out loud, in a doctor’s office, more than once. And you’ve probably left without a satisfying answer. After more than thirty years living with fibromyalgia, like many of you, I am very frustrated. We are still going around in circles debating each other.

Here’s the truth, and I’d rather give it to you straight: we don’t yet know the single cause of fibromyalgia. If we did, we’d likely have a treatment that reliably worked for everyone, and we don’t have that either. I know we may not know the cause, but we should keep searching for answers. Science has moved forward, and the picture emerging explains a lot of what you live with every day.

The shift that changed from “where it hurts” to “how pain is processed”.

For a long time, fibromyalgia was treated as a problem in the muscles and joints, and you were sent to a rheumatologist. But the strongest current evidence points to widespread neuroinflammation in the brain and nervous system, and to how it processes pain signals.

In 2017, the International Association for the Study of Pain formally recognized a third category of pain called nociplastic pain. Pain that comes from a change in how the nervous system processes signals.  Fibromyalgia is now considered an example of this category.

The core idea is central sensitization. Think of your nervous system as having a volume dial for pain. In fibromyalgia, that dial gets turned up and effectively stuck there. Incoming signals get amplified, and the body’s built-in “turn it down” system doesn’t work as well as it should. So a sensation that wouldn’t register as painful for someone else can be genuinely, measurably painful for you. That’s not fragility or imagination. It’s a real, physical difference in signal processing, shown on brain imaging and through nervous-system testing.

Still, it leaves us with unanswered questions about what causes this in the first place.

Several threads, likely working together.

There isn’t one switch. The current thinking is that fibromyalgia develops when several factors line up. Here are the ones with the most support behind them:

• Genetics and family history. Fibromyalgia clusters in families, and having a close relative with it raises your risk. It isn’t one “fibromyalgia gene”; it appears to be many small genetic influences that shape how sensitive your pain system is to begin with.
• A trigger event. For many people, symptoms take off after a specific stressor: a physical injury or accident, an infection, surgery, or sustained emotional stress. The current understanding is that these events can act as the tipping point for a nervous system that was already primed.
• Small nerve fiber changes. In roughly four out of ten people with fibromyalgia, some studies have found a reduced density of tiny nerve fibers in the skin. What this means is still being worked out. Whether it’s a cause, a consequence, or a feature of a subgroup is still being worked out.
• The systems that run in the background. Disrupted deep sleep, an over-revved stress response (the HPA axis), and autonomic nervous system dysfunction all show up frequently and can feed the cycle.  Poor sleep worsens pain, pain worsens sleep, and around it goes.
• An emerging immune angle. This is the newest and most intriguing thread. In a 2021 study, researchers at King’s College London and the Karolinska Institute took antibodies (IgG) from people with fibromyalgia and transferred them into mice. The mice developed fibromyalgia-like pain sensitivity. Antibodies from healthy volunteers didn’t. It’s early, it’s only shown in an animal model, and it won’t rewrite everything overnight, but it opens a genuinely new door, suggesting the immune system may be part of the story for at least some people. It’s worth watching closely.

What this actually means for you?

I want to be careful here, because hope and honesty have to sit together.

Not knowing the exact cause doesn’t mean you can’t do anything to improve your quality of life. We treat plenty of conditions well before we fully understand them. Your pain is real. It has a physical basis. If you’ve ever been made to feel like you were exaggerating or imagining it, the science is firmly on your side.

What do you think caused your fibromyalgia? What was happening in your life when it started?