12 Aug How Pain Works
When you are looking for a solution to persistent pain it really helps to understand what you are dealing with.
Before I go any further I just want to be clear. All pain is real. Your pain is real. My pain was real. It is never ‘just in your head’ or psychosomatic or ’emotional’. That kind of comment shows a fundamental misunderstanding of pain.
If something is impacting your life day in day out you deserve to understand it, so you can make the best choices in how to deal with it. Because it is a complex subject, it is hard to summarise, so please bear that in mind as you read….
We tend to think of pain as being something caused only in our bodies. If we think about how it works at all, we maybe think of “pain receptors” sending a signal of pain down the nerves, to our brains.
This fits best with an acute injury e.g. a broken leg
BROKEN BONE >>>>pain signal>>>>>BRAIN
Brain says: PROBLEM IN THE LEG!!
This all seems straight forward until the broken leg has fully healed and there is still pain. In this case, if pain is supposed to be a report about damage to the bone, and the damage is all healed, why would there still be pain?
So, yes, it’s a bit more complicated than a read out of damage from the body…..
Pain is your brain’s interpretation of all the information it has about the situation.
Sounds odd? Bear with me.
Information comes in to the brain all the time via the nervous system, and it has to filter and interpret it all. You can’t be aware of, or concentrate on, everything at the same time, so the brain just presents us with the most relevant stuff. This works visually, e.g. you don’t notice what’s going on in your peripheral vision if you are concentrating on your computer screen. And with your hearing: your brain will filter out background conversations in a noisy pub, but if someone mentioned your name in the hubbub your attention would be caught!
Information from the body is one of those things competing for our attention.
Your body has sensors in the tissues – these are nerve endings that report on things like pressure, temperature or chemical changes and send information to the brain. There are no special pain sensors, it is just when there is a lot of ‘worrying’ information coming from a body part it may be interpreted as pain. With a broken leg there are a lot of damage signals from the tissues so pain is inevitable. But even in this clear cut situation you may not always feel pain. Pain can be delayed because of shock for instance: pain is ‘put on hold’ until we are ‘safe’ to deal with it.
You may have noticed this variable response to what the body sensors are saying when you get a dead leg. When you have been sitting in a position for too long chemical changes due to the restricted blood supply occur, and this will cause the chemical sensors to send information. At what point you pay attention to it will vary though. If you are bored, any slight discomfort might register, and you will fidget to get comfortable. If your brain is busy with other things it might wait until the signal seems very urgent before it tells you that you really need to move. This time your brain left it so long you can’t even bear weight on that leg!
Pain is what we experience when the brain decides that the information from the body sensors is something to worry about.
It is an unpleasant sensation, so it acts like an alarm signal to get your attention, so that you protect yourself. You remember painful events very clearly, so you will avoid getting hurt again (in general – sports like skiing seem to be an exception!)
It is a danger signal that your life, or something very important is at stake, so you must respond. Pain was useful in our evolution, but also still today, to prevent us hurting ourselves or to let injuries heal.
Because it has this important job as a danger signal, it can err on the side of being oversensitive.
In the case of that broken leg that has healed, but is still painful, the information from the body sensors is now at a very low level because healing has occurred.
So why would pain persist?
These are just some examples of why:
The area of the nervous system dealing with the leg has been very “busy” for many weeks and has become “sensitised”. Any little bit of information from the tissue sensors is then paid attention to much more than normal. This can make just light touch seem painful, for instance, because any slight pressure is overinterpreted as pain. Sensitisation is caused by physical changes in the nervous system, and is a very common factor in chronic pain.
Muscles in the painful area “guard”, tightening around the injury to prevent movement and this can exacerbate pain. Gentle mobilisation can help prevent this, but it can remain an unconscious pattern even after the area has healed.
“Flight or fight” hormones and systems are activated. If the pain is ongoing this activation is also ongoing. This has many affects e.g. it can make it more difficult to rest. Being sleep deprived makes everything seem harder, and pain is often worse when you don’t have quality rest.
All experiences involve thoughts and emotions, and pain is no exception.
If you have have an injury as a child, and recover at home, being looked after by your parents, your brain will probably decide that, although unpleasant, there isn’t too much threat to your whole existence. You feel cared for and worry free. So, the brain ‘decides’ that, once the bone and other tissues stop signalling a problem, that the threat is gone, and no more pain is felt.
But, maybe as an adult, dealing with a injury with little help and worries about getting back to work it might all feel a bit different. If you had had a horrific injury in past, for instance, you may relive that experience a little with this new injury, and that old sensitivity of those parts of your nervous system will influence how much the brain should pay attention to the leg. This means that the brain will generate a bigger alarm signal that may well carry on for longer.
So, you can see there could be many factors that could affect why the same injury could be more, or less, painful for the different people, and more or less likely to turn into persistent pain.
These factors come into play to a greater or lesser extent whatever the source of pain.
If you have an ongoing condition, such as arthritis, where there will be signals from sensors in the body all the time, you are probably going to experience some pain. However, that doesn’t mean you cannot influence your pain. There are lots of powerful ways the nervous system can dampen pain and learn to pay less attention to the signals from the body sensors, when they aren’t useful to your wellbeing. You can also learn to undo some of the less helpful responses we often have unconsciously to pain such as tensing up, or avoiding certain movements.
If you have read this far, please don’t misunderstand: you might need a brain to experience pain, but that DOESN’T mean it’s just in your head. I know that’s not true from personal experience, and it is not what this all means.
You can’t just think yourself out of pain. Be positive, and it will all go away. You also are not responsible for causing your pain to persist. Most of the factors in why persistent pain develops are unconscious, or out of your control eg genetics.
However, we are often given simplistic explanations of our pain, as just in the body, or just in the mind, and that doesn’t help us.
Knowledge is power when it come to pain.
Understanding pain’s complexity gives you access to all sorts of tools to help it. If you just treat the body without ever considering the mind, and how the nervous system works, you might get better, but it’s less likely because you are missing major bits of the pain puzzle.
Are you working on reversing the sensitisation of your nervous system? Do you use relaxation, or the power of your attention? Has anyone shown you how best to use exercise in rehabilitation? There are so many aspects to improving and recovering from persistent pain. Why not use all opportunities to help your pain and to improve your wellbeing in a more general way too?