What is pain? 

We need pain to survive. People with genetic defects who do not feel pain die young because they get damaged without the protection pain affords. Pain is the vital warning system and behavioural coach which soft-tissued humans need in a world of hard objects. 

The big surprise, which Monty Lyman points out in his book The Painful Truth, is that pain is the sum of BOTH physical sensations AND a neurological process. This observation is a mainstream medical consensus but for me, it was a revelation. My own hope is that if the conscious brain understands this, the unconscious part of the brain may generate less unnecessary precautionary pain. 

Pain is not felt as a physical sensation sent directly in its raw form from the site of the sensation.  The brain, having received sensory messages from so called nociceptors on or near the skin, analyses the context and decides whether to add pain to the physical sensation being received. It can markedly increase or decrease the pain-signal based on the analysis it does. Nevertheless, pain is very real and is not ‘imagined’ into existence in some dreamy, feckless way. Pain hurts. 

Clinicians will often note that for particular patients there is no obvious medical source of the pain. This is common but discouraging for the patient whose conscious mind has played no role in the neurological process which created the pain.  Following a serious motorbike accident, I am such a person. 

Monty Lyman in The Painful Truth, imagines pain as the actions of a Ministry of Defence. The first action is the front line troops, the nociceptors, detect all sensations including those that may do harm like a cut, a blow or a burn. They send signals back to the brain which then does some analysis to assess the context. A feeling of a shoe on a foot, confirmed by seeing the shoe or remembering you put it on earlier, can be ignored. But if the brain judges the cause of the sensation to be dangerous, then the brain adds pain to the incoming sensation. The value of this transformation is protective for the whole organism because it causes, indeed enforces, protective behaviour. A hand burned in a fire is pulled out and cannot be voluntarily put back in. Up to six areas of the brain are involved in this analysis which is a complex and comprehensive process; as it should be. Analysed data is always more valuable than raw observations!

The brain’s first point of reference for this analysis is context. If a patient has broken a toe scoring a winning try and is being cheered by rugby team mates, then the brain reads the environment as safe and positive, so it will only add a low pain message, or perhaps none at all, to the received sensation. The same toe broken in a workshop where anxious comrades are asking if the patient is OK, is read differently by the brain and a stronger pain signal is added. Many badly injured people feel no pain at all until they actually see their injury and realise how serious it is.  I recall a small boy who had his knee cap taken off sliding down a hillside. He was cheerful and calm until his trousers were rolled up and he saw the damage at which point he became hysterical.  He was distressed by what he saw, not by what he felt. 

Monty Lyman quotes data from a particular sample which shows 70% soldiers from the battlefield arriving in hospital reject morphine on the basis they are not in pain. This is logical. They were on a battlefield but now they are in a much safer hospital in a rear area. The brain made a rational decision they were under less threat and so diminished the pain signal. Whereas civilian victims from traffic accidents arriving in hospital report much more pain for similar or less injuries. They were previously in a comfortable car, listening to music and drinking coffee but now they are in A and E with other dangerously ill people and they feel less safe. The brain rationally decides the body is in more danger and amplifies the pain signal accordingly.  In summary, levels of pain depend as much on context as the actual injury. (The same is true of cold. I was in a snow hole in Alaska for 3 days. I was warmer when I was cheerful than when I was miserable. In any group of mountaineers, cold feeds misery but misery feeds cold. There is a link between physical and mental state)  

So in Monty Lyman’s military analogy the same thing happens. If the MOD gets a report that a soldier was shot in the foot in say Canada it would not assume there was danger more broadly. It might assume the shooting was a robbery or an accident. But the same shooting in say Afghanistan would be seen very differently. The context was more dangerous so more reaction is justified and more protection (ie Pain) would be the right policy. 

Another part of the brain’s analysis is history. Monty Lyman says the brain also searches the archives.  The brain remembers an old injury, even if it is fully healed. It knows there might be weakness in that area. So even if there were only weak sensation-signals from the nociceptors in the area of the old injury, the brain might well suppose that more protection was justified and therefore amplify the pain signal from that old injury or even from a similar one nearby. 

I currently have three types of pain. Back pain because a metal frame has replaced two burst-fractured vertebrae. In my mind the back pain is fully justified by the actual physical situation.  Metal was screwed into surviving bones around the site of the injury. Nerves in those bones feel a new sensation, presumably screws, and send out signals. My brain adds a bit of precautionary pain to those signals to discourage heavy lifting, awkward sitting etc. It is fully understood by me and all pretty manageable. 

But also, much of my skin feels like a fizzy drink. Pins and needles make parts of me, which were completely uninjured, very sensitive to the touch. When I am in water I instinctively avoid having the water line on these areas because it hurts.  This fizzy-pain was by far the worst of the three pains until my GP did two things. She explained why this pain arose (because damaged nerves are regrowing) and secondly gave me drugs that interfere with the neurological component of pain. Thus, my brain is now adding less pain to the sensations the nociceptors are sending.  Partly, because drugs are blocking them from doing so and partly because my improved understanding of the context makes it less necessary for the brain to add protective pain.

My last debilitating pain is a sort of internal pain just below my diaphram. This is where the GP and I struggle. I want it explained to me and like most patients before reading Monty’s The Painful Truth, I think pain is a sensation that gets transmitted from it’s point of origin. My GP explains the nociceptors in the abdomen are fewer and are not wired accurately like those in the fingers, so the origin of the pain is not where I think it is. She points out I have had multiple scans which have eliminated anything serious but we still cannot know exactly what it is. Modern medicine has its limits. She was too polite to say my brain was creating this pain; but that is surely partly true. At a minimum it is mislocating it. When I rub or poke the area, it is fine. 

While my GP was explaining all this I thought of the dissection of a criminal, inelegantly named Old Green Hag in Japan in the 1830s. This dissection showed that Japanese understanding of anatomy had fallen behind in the two hundred years Japan had been closed to outside knowledge. The discoveries made in the dissection played a role in forcing Japan to open up to the outside world and ending the shogunate. I had assumed that today doctors knew everything worth knowing about our bodies but my GP explained they do not. This knowledge, that I am not alone in my confusion and that it may well be my brain that is creating this particular pain for some other reason, is calming and helpful. I hope finding out why it is doing this will eventually reduce the pain. 

I have also noticed that when I get tired fizzy skin pain comes back. It is as if my brain feels the need to recreate some pain to slow me down and make me rest. 

The surprising conclusion is a sufferer’s mental attitude can alleviate pain. Do buy Monty Lyman’s book, The Painful Truth. I am very lucky to have my doctors and physios for whom my enquiries must be rather trying. Thank you.