I have written a series of blogs on pain in the past. Recently I have read a book that makes it all astoundingly clear. The actual book I read is called Therapeutic Neuroscience Education. So far it is only available from the US and the publisher is OPTP. The central section of the book has many examples explaining why we can hurt for such a long time after an event. OPTP publish this section alone in a simpler – and cheaper – version of the same book: here is a link to it: Why do I hurt? by Adriaan Louw. The most important reason to understand what’s going on when we suffer long term pain is that the best way of reducing long term pain lies in understanding it and thus reducing the fear of it.
The reason for pain is for survival: the brain needs to know so we can react.
There is a condition we can be born with where we cannot feel pain – congenital insensitivity to pain. These people do not live a long life. When we hurt ourselves and feel pain, the brain is immediately interested; it is extremely interested in every pain we are aware of. Where long term pain is concerned, this is part of the problem.
There is a difference between short term, or acute, pain and long term, or chronic, pain. But there is also a similarity: when we experience pain, the nerves responsible for telling the brain that we hurt are triggered. The difference is how much stimulation it takes to trigger those nerves. And circumstances surrounding the pain also play a part. It is very important to understand that we are far more complex than a car. The car stops going; we somehow get the car to the garage. We pay an enormous bill for replacing a sprigglestif1 that cost 50p, but seemed to require the garage to take the entire engine apart over 3 days. We weep. But the car goes again. We crash the car as we drive home, unable to see because of tears of financial pain. We get whiplash. 30 years later, we are in great pain. We stop exercising and we don’t know why.
In our body, there are about 45 miles of nerves travelling through the body and connecting all body parts. They are all connected like a load of roads, but they work like an alarm system. Our nerves have a bit of electricity flowing through them at all times. They have thresholds of excitement, and when the electricity flows enough to breach that threshold, an alarm is sent up to the brain for analysis – and maybe a bit of action.
So step on a nail and we should immediately know about it; we shout out, we take our foot off the nail as fast as possible, we hop about, we walk funny. The nerves in the foot send an extremely rapid message to the brain that we are in danger and we need to do something about it NOW. Briefly, the whole nervous system lights up. And continues to light up as we try to walk on the foot. In due course, the foot heals and the alarm system calms down.
Seems simple. However, if we step on the nail whilst crossing the road in front of a car being driven rather wildly by a weeping person, the brain decides to ignore the pain from the nail and lets us sprint to safety. Once the car has gone past, we will then notice our en-nailed foot and start hopping about, shouting and so on.
This means the brain has made a judgement call on its job of ensuring our survival – the pain in the foot was not as important as getting out of the way of the car. We ignored the foot pain. Incidentally, we have amazingly powerful painkillers in us, released by prompting from the brain. Learning about how to control long term pain partly works by releasing these innate chemicals.
So pain is pain. It is real, whether it is caused by a wasp sting or long term back ache. The difference between the two pains is how much stimulation the pain nerves, the nociceptors, take to be triggered to relay a message to the brain. The threshold is the same, but it takes much more stimulation when the tissues are normal than when the tissues have suffered damage and the brain is on the look out for further insults. It takes less to fire up the alarm. A simple analogy: when a burgular alarm is working properly, the window has to be smashed to set it off. When we are suffering long term pain, a leaf blowing against the window will set it off. Not good.
- Sprigglestif – made it up. But I have been charged a lot of money to replace some piddly little washer at the bottom of the engine. [↩]