Your Brain's Best Guess Might Be Driving Pain

A concept I find myself coming back to repeatedly with patients in chronic pain is recognising that the brain is always one step ahead of the body.

What do I mean by this. Well, this sits at the heart of something called predictive processing, and understanding it has shifted the way I think about pain.

There are some fairly persistent but out of date ideas about how pain works. It goes like this: something goes wrong in the body, a signal travels up to the brain, the brain registers pain. Like a fire alarm going off when there's smoke. It is why we call pain the harm alarm. But that's not quite how it works because the brain is not a passive receiver.

Your brain is not sitting around waiting for information from your body. It's constantly generating predictions about what's happening, using everything it knows about you, your history, your past injuries, your past experiences and then assessing whether the incoming signals match what it expected.

When there's a mismatch, or when the prediction is "this situation is dangerous," the brain responds accordingly. The system goes on high alert which means more muscle tension or bracing, pain (or more severe pain) and maybe other feelings such as increased heart rate or sudden feelings of anxiety or a sense of being on edge.

Not necessarily because there was an issue in the tissue, but because there was a prediction that the body was under threat.

This is one of the reasons why two women diagnosed with endometriosis can have completely different lived experiences.

Despite the same diagnosis, and often the same stage, one woman has almost no pain, while the other spends much of her month pushing through to keep functioning despite the pain.

The issue in the tissue is similar, but the brains predictions are not.

Predictions are shaped by a lot of things: past injuries, previous treatments that didn't work, frightening things that were said by well-meaning health care practitioners, the exhaustion of not knowing what's wrong or being told nothing is wrong (it normal to experience this much pain with your period), and the accumulated experience of a body that has felt unreliable for a long time.

None of this means the pain is not real. Pain is always a real experience. What predictive processing helps us understand is that the experience is being generated by a brain that's working from a particular set of assumptions and some of those assumptions may no longer be accurate or helpful.

Think about what happens when you go to bend forward, or lift something, or try to get back to exercise.

For many people in persistent pain, there's something that fires before the movement even starts. A kind of internal verdict: this is going to hurt, this is risky, my back can't handle this, something is going to go wrong.

This is a learned prediction, built up over time by a nervous system that has been in protective mode. It's doing exactly what it's designed to do.

Learned Predictions

Are reinforcing loops created by a nervous system in protective mode - it’s doing exactly what it’s designed to do.

The problem is that predictions built in one context, say, immediately after an acute injury but can persist long after the original situation has resolved. The brain keeps running the old model even when the circumstances have changed. And every time movement is avoided, or pain spikes and confirms the fear, the prediction gets reinforced.

This is one of the key reasons chronic pain is so persistent. It's not just about tissue. It's about a self-reinforcing loop between expectation and experience.

If predictions are active ingredients in the pain experience, then understanding your own predictions is part of the treatment.

This doesn't mean abandoning hands-on treatment, or movement, or addressing real physical contributors. Those things still matter enormously. But they work better when we're also paying attention to what the brain is anticipating.

Here are some things that can help shift that prediction environment:

• Education about how pain works. Not in a way that dismisses your experience, but in a way that gives you a more accurate map. When you understand that your nervous system has been in protection mode and why it starts to make sense without being a life sentence.

• Graded exposure to movement and activity. Gently, expanding what your body does in a way that starts to update the brain's evidence base. Each experience of moving without pain (or with less pain) is a small recalibration, and perhaps one that sets up a positive prediction error, telling the brain and nervous system that ‘this time it didn’t hurt as expected’. So, the goal here isn't to push through pain, rather it's to give the nervous system new information.

• Getting curious about your own predictions. What do you believe is happening in your body when the pain flares? What's your concern about moving? The answers reveal a lot about predictions that might need updating.

• Validating the experience without reinforcing the threat. That is, your nervous system learned to respond this way for a reason, and it can learn something different.

Where to From Here

If you've been living with persistent pain and you've been told the answer lies entirely in a surgery, or a supplement, or finding the right thing to fix, I want you to sit with this for a moment.

Your pain has a story. And that story includes your biology, yes, but also your history, your nervous system's learned responses, and the predictions your brain is currently running about your body.

Addressing all these layers isn't a less serious approach to pain. It's a more complete one.

And understanding what your brain is predicting? That's often where some real changes can be made.

I’m a naturopath working with people in chronic pain. If you'd like to explore what a more complete approach to persistent pain might look like for you, please get in touch.