How our Understanding of Pain has Changed - and why that matters to you

What we know about pain has grown and changed - years ago we had a pretty limited understanding of pain and the way the body identified a feeling as pain. New research has made us question our knowledge of pain and has led to a new understanding of it.

Theories about what causes pain stretch back to the time of Descartes the French philosopher (1664). Descartes believed that the nervous system was fixed or ‘hard wired’ like the wiring in your home.

In your apartment or house you flick a switch, electricity flows and something works as a result. This original model of pain was similar; something unpleasant like heat or injury caused special nerves to send a signal to the brain which interpreted the feeling as pain.

It was assumed that the greater the unpleasant pain stimulus, the greater the pain response. For example if you had a small injury you had a small pain but if you had a bigger, more serious injury you got a much bigger pain.

An illustration from one of Descartes books (courtesy Wikimedia) descartes model of pain

This model assumes that pain is a reliable signal of tissue damage or harm - that this is a stable and reliable system. Many people I meet still believe this to be absolutely true and think that the amount of pain felt is directly linked to the amount of damage or injury. Is this your understanding about pain?
However, we now know that this isn’t true at all
Our understanding of the pain experience has raced forward and changed in recent years and we now understand a lot more about pain and its interpretation by the mind. We have a new model in which our understanding of pain is redefined.

Our understanding of what causes pain has changed

We now know that the experience of pain is relative and depends on your situation and the context in which the pain is felt. 

It is perfectly possible to have pain in the absence of any tissue damage and have no pain at all in times of great injury.

There are some great examples of where we have seen this happening in real life. There are examples of soldiers who have been shot and didn’t realize until later. I have treated squash players who have totally ruptured their Achilles tendon – this is a severe injury – many of them described a dull thump in the heel area, often they turned to their opponents and accused them of hitting them with a ball!  I have read about shark attack victims who had bites taken out of them and didn’t feel a thing until later when they were safe. Someone I know recently had a really nasty dog bite, she needed a skin graft it was so bad, yet she felt virtually no pain, she said it felt like a graze.

If pain is a reliable indicator of tissue damage why do some people have cancer and not realise it – the cancer is certainly causing damage and harm?

Pain is not a reliable indicator of tissue damage.

On the flip side of the coin you have probably heard stories of people who have had limbs amputated - and yet they still feel pain from the missing leg or arm, this is called phantom limb pain.

I have worked with many people with lower back pain who have minimal tissue damage and yet suffer from extreme pain. Scans, tests and investigations show nothing damaged or harmed yet they suffer terribly.

How can this happen?

.Brain MRI

It’s all to do with our brains (image courtesy Wikimedia)

More about how our understanding of pain has changed - Part Two -

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