Understanding Pain

Have you ever had one of those pains that seems to just appear from out of the blue for no reason, no injury, no incident and thought to yourself – what’s all that about?

Damage some part of your body – pain signal is sent up to your brain – get pain

Simple right!

Well …. Yes and No.

A lot of pain is explainable by the above simplified scenario, for example: roll your ankle, strain a ligament, get pain – known as acute pain, makes sense.

But this is not always the case. What about those pains that seem to turn up for no reason, they appear one day and then hang around for longer than you think they should.

We have learnt a lot about pain in recent years and in simple terms, it turns out it is quite…… complex.

What we now know is that the brain is receiving massive amounts of data from the outside world at any one time. This data comes through the body’s senses and more. Sound, smell, touch, taste, sight, proprioception and nociception are some of the data streams the brain is receiving. Nociception is the important one here which we will cover in a moment. The brain only has a limited capacity to deal with all that incoming data and so it prioritizes the data in order of perceived importance: Acknowledging and processing the seemingly important data and essentially ignoring the rest.

For example – right now your brain is receiving information from your ears in the form of sound. Most of it is background noise like passing cars on the road outside, bird noises, maybe the sound of machines, but your brain is not prioritizing those sounds because it does not think they are important. Now if a loud noise suddenly occurred then your brains attention would be drawn to that, and you would become aware of the passing car noises, bird sounds etc… In fact, I bet right now, because this article has drawn your attention to it, you are now acutely aware of those background noises. It is all about priorities.

Nociception is the information a brain receives from the body regarding possible danger to our tissues. It is described as an incoming “warning” signal, not a pain signal. The pain comes later as an output from your brain.

Once the brain receives these warning signals then the brain does some prioritizing of these warning signals. If they are sufficient enough to warrant attention, then pain is the product of this process.

In short, if the brain determines that the nociception is a serious enough warning signal, then the brain will output pain to make you aware of the situation for you to act accordingly.

So it may be the case that the reason your body part has become sore, even though you have done nothing to make it hurt, is your brain is making the calculation that it is now time to take note of the things that are happening in that part of your body, whereas the days before it did not think it warranted your attention.

The really interesting and complex part of this is the prioritizing process and how this process is affected by other factors associated with your brain.

The prioritizing process takes place within the confines of your brain, and as such, the “state” of your brain has a bearing on the prioritizing process. Factors such as fatigue, stress, anxiety, beliefs etc… set the baseline for your brain and the state in which your brain prioritizes your input. If you are relaxed, content, sleeping well and generally going OK in life, your brain may not feel it needs to prioritize your nociception, but if you are worried about your job, paying your bills, not sleeping well, have anxiety and are generally not feeling great then the brain may prioritize your nociception and give you pain. Factors such as stress, anxiety etc… do not directly give you pain, but may contribute to the pain levels you experience.

So, it is more complicated than it would seem, but it does give us an explanation as to why one day there can be no pain, then the next day something is painful, for no apparent reason. This is known as the biopsychosocial model of pain and this does a great job of explaining all kinds of pains.

In addition to this information about pain, there can often be other signals present in your body parts that may precede pain outputs and be an indicator of what may be coming. Feelings of tightness, weakness, giving way, swelling, catching and stiffness, for no apparent reason, may be possible indicators of incoming nociception. Your physiotherapist is best placed to assess these musculoskeletal issues and is a great first point of contact.

You can also learn more by watching the ‘Tame The Beast’ video by guru Professor Lorimer Moseley here, or popping into see us and purchasing our ‘Pain Book’ for your reading and discussion with our physiotherapist. 

Written by: Adam McKee