What is pain?
Pain is all about meaning. What does this mean?
Our brain weighs up how dangerous is the current situation or experience and then sends a message about what to do about it. When there's a 'Danger situation'; such as stepping on glass in bare feet, we need our brain to send a message down to 'make our foot hurt', so we can behave in a way to get ourself out of the situation. It won't hurt if your brain thinks you're not in danger.
Our Brain evaluates for true danger compared to the message coming up from the tissues and the spinal cord. The brain can then evaluate that the message is not as dangerous as the spinal cord thinks - the brain then produces descending inhibitory drive, sending inhibitory pain mediators to the spinal cord to settle things down, dulling our initial pain.
A few examples:
Soldier getting shot in war doesn't feel pain as the brain weighs up the context of the situation - is it in the best interests of survival to be feeling pain right now? Obviously not, so the brain releases natural pain killers and stops the danger message, deciding that pain right now is not in the best interests of survival - you need to be able to run and get out of there in order to survive!
Or a sports final where we are injured in the last quarter. Is it worth having pain? Is victory, a premiership and lifelong glory more important than this tissue damage right now? There are many examples of this, where players had a horrific injury in the grand final, only to play on as they couldn't feel the injury. They subsequently become very sore post game!
Phantom limb pain: the brain thinks the leg is still there and at times, thinks the leg is in danger, producing phantom limb pain.
Pain can go the other way too. If you put a pin in a violinist finger it will hurt more than if you put a pin in a non-violinist finger. Obviously there's more of a threat or a challenge to the violinist and the brain decides that it's in their best interest to protect that valuable finger. More threat = More pain.
A recent study did an Experiment: recruited normal healthy volunteers (probably not normal as they volunteered for a pain experiment!). They were Randomly put in 2 groups. Both received a Cold piece of metal on the back of the hand. One group was shown a red light as they were touched by the cold metal, the other group was shown a blue light. They were then asked; How much does it hurt? If they saw the red light they said it hurts more on a 0-10 pain scale, than if they saw the blue light. What was different? Nothing, the stimulus was the same, but the meaning of the stimulus was different. Pain is all about meaning.
Another study put a large head stimulator onto participants heads. They made sure the subject could see an intensity dial. The stimulator was a sham that didn't work and did absolutely nothing, but the participants didn't know this. All they could see was the intensity dial. The results showed that pain increased proportionately with an increase intensity. Even when there was no actual intensity/output from the stimulator, if the individual just thought that the intensity was being turned up, they experienced more pain.
This shows that pain is all about meaning. If your brain thinks you're in danger it will produce pain as an output, if it thinks you're not in danger, you won't feel pain.
When pain persists it's deciding to protect that part of the body. Sometimes the body doesn't actually need protection, but the brain thinks it does. The brain makes this decision based on past experiences, knowledge of the injury., information given to someone, X-rays, scans and also cultural beliefs.
The drug cabinet in the brain - deep in our brains we have areas that work together to produce remarkable pain killing drugs. Opiods, endorphins, serotonin and morphine are some of these. These are made in the 'drug cabinet in the brain'. Some of these natural pain killers are ten times more powerful than normal morphine.
How do they work?
These chemicals are made and they trickle down the spinal cord and into the brain. If these pain killers are trickling down into the spinal cord, then impulses from the body (telling you about warmth, stretch, danger) can be stopped at the spinal cord.
How do we open and close the cabinet?
Well it's under control by various areas in the brain; they talk to each other, they weigh up the situation and decide whether they should open it or not. If open, there will be no pain, if closed there will be pain. The key question the brain has to answer is; 'is it worth having pain?'
If you run and stub your toe while crossing the road, you have to get out of the way of a car. Therefore, it won't hurt. The Brain decides - it's not worth having pain. The cabinet opens.
I've seen people in the clinic with horrible looking scans (MRIs, Xray) showing various things, such as multiple crush fractures, multiple bulging discs in their lower back, and all sorts of issues that you would think would be horribly painful, and yet they feel no pain.
Why is this?
Well, the issues have happened slowly over time, and the brain has decided that there is no threat from the disc or the vertebrae, and so has decided not to produce pain. Also, the brain can become 'satisfied' that everything has been done to heal the tissues and so decides that producing pain is not worthy.
What is the key to opening up the drug cabinet in the brain?
Understanding, having knowledge, having support and setting goals,
Knowledge is the greatest pain liberator of all. Particularly knowledge of how you're body and how pain works.
Message us for references and acknowledgement to David Butler for the 'Drug Cabinet in the Brain' Youtube video.