How and Why We Feel Pain

In order to understand the “pain stuff”, you first need to know
that your brain is an amazingly clever organ…
By Dr Claire Richardson – Osteopath

Warning: This blog involves some neuroscience. You might even change your own brain while reading it. Intrigued? Read on!

The topic of neuroplasticity gets me really excited. The science is completely fascinating (even if you’re not a nerd!) and there has even been studies that have shown that simply learning about how pain works may be able to reduce it. How cool is that?

First things first: in order to understand the “pain stuff”, you first need to know that your brain is an amazingly clever organ.

We used to think that we had a “blueprint” of our brains, meaning that one part would be responsible for sight, another for hearing, another for sensation and so on. We used to think that this was pre-set and was “mapped” the same in everyone.

What we now know is that brains are adaptable, changeable and plastic. If your brain’s area for taste is damaged, it has the capacity to change the neurons somewhere else to pick up where the damaged area left off. How cool is that? WE CAN CHANGE OUR BRAINS!!!

Now, the pain stuff. How do we feel pain? Why do we feel pain?

Unfortunately, pain is never an accurate representation of “damage”. If it was, it would make our jobs heaps easier, as diagnoses would simply follow the formula: lots of pain = lots of damage; no pain = no damage.

We know that there are heaps of people out there with terrible-looking MRI or CT scans but NO low back pain, and alternatively people in incredible amounts of pain but nothing seen on their scans.

Pain is a defence mechanism. It’s there to warn you away from potential dangers.

For instance, if I rub up against something sharp, my brain interprets lots of incoming information and recognises that this might be dangerous situation. My brain then decides to make it hurt, so that I can take action and move away from the potential danger.

So, pain doesn’t actually exist until your brain decides to make it exist. 

There is no such thing as a “pain nerve” or “pain receptor”. There are lots of other types of receptors relaying information like touch, temperature, sharpness or danger, but not pain.

All of these things – touch, temperature, movement, sharpness, dullness etc – are types of information going INTO our brains. In other words, they are an INPUT.

There are lots of other inputs to your brain as well. They include emotions such as fear, anxiety and stress.

Other inputs are things like the information we gather from moving around and exercising. Or even things like our immune state or hormonal state.

Memories and past experiences are even inputs, and really important ones that I’ll mention further down.

All of this information comes together as a big, jumbled mess within our brains. We’re constantly having messages being sent to our brains, which our brains have to assess and then act upon.

When the brain encounters a possible threat of danger, like the information it would receive about something being sharp if I brushed up against a barbed wire fence, for example, it then assesses all of the other INPUTS, such as my level of fear or worry, my hormonal state, my immune state, what I’m doing with my body at that point in time, and also my memories about similar circumstances.

When my brain looks back at my previous experience, it might remember the time that my young sister accidentally (probably on purpose when I think about it) cast a fish hook into my upper arm that almost required stitches and then got really infected.

In someone else, the brain might remember the slight scratch they received when walking through the garden and then promptly forgot about.

Those two previous experiences supply vastly different inputs, despite the sensation input (the sharpness) being identical.

My brain is likely to think: “Whoa, got some sensory information here that’s really similar to when I was 10, and it was a BIG DEAL and I got sick and really scared of it and have since harboured a fear of going near my sister when holding a fishing rod. I don’t want that to happen again. Nuh uh. Here, I’ll make it REALLY HURT so that we move away from the OBVIOUSLY dangerous situation. Duh! It was last time so it has to be again!” (It’s not actually an obviously dangerous situation, but my brain doesn’t know that.)

Someone else’s brain might think: “Hmm, got some sensory information here that’s really similar to when I was 10 and scratched myself on a tree and then forgot about it. Meh, no big deal. Not too dangerous, don’t need to dish out too much pain here.”

Either way, pain is always an OUTPUT of the brain (something that the brain makes happen) as a result of the information it has at hand. Other outputs can be tone (tight muscles) or a change in hormone or immune states.

Why is all of this important?

Because if you can change an input, you can alter the output.

There has been some really encouraging studies showing that once people understand how pain works a lot of their fear and anxiety regarding their pain, and what it potentially means, is alleviated.

Therefore, their pain is reduced too. (By changing the emotional INPUTS to their brain.)

We also know that exercise helps to change inputs, by changing the information that our brains receive regarding the safety of movement as well as by proving to our brains that we’re not broken and that exercise isn’t a potentially dangerous situation.