This blog became SO long that I've ended up splitting it into 3 parts. I knew I wanted to begin to write extensively about pain when I decided to set up this Substack. I wasn't prepared for 4000 words on a single blog! So I have split it up for ease of access.
So, without further adieu, here is Pain Is Complex (Part 1).
The Thing.
There is an idea. It pervades the vast majority of clinic rooms, sitting rooms and bedrooms when it comes to people and their pain.
This idea that if we could just find THE THING that's causing the pain, we could deal with it once and for all.
The well meaning therapist might hunt for “the thing” while you're in their clinic.
You might wrack your brain trying to figure out what “the thing” is when you are lying in your sofa or in your bed at night when you can't sleep because of the discomfort that “the thing” causes.
The reality of the situation is that there cannot be ONE THING causing pain. If pain or symptoms were that linearly constructed and created, they would be simple to solve.
And yet, pain and pain related disability are some of the leading causes of absence from work, medication use, social exclusion and general unhappiness in life.
A client in the clinic recently asked me if I thought that we “just had to find the thing causing the pain to sort out her symptoms or if it was a bit of everything that's been going on”… I nodded and said “well it ain't the one thing”…
So let's take a deep dive into pain and all the things…
Pain is Biological.
Of course pain is biological David, I hear you say! Of course it is related to my body! For most people, this is as far as the thinking about pain goes. I’d like to explore a little deeper with you.
Did you know:
“If a surgeon were to open your body with a scalpel, right at the area that hurts the most, not one single person on the planet (medical professional or otherwise) could take a look inside your body and point out or touch this thing we call pain.”
They would find all sorts of tissues and even find changes to those tissues but they could not point to anything and say “there's the pain”.
As a physical, tangible, touchable entity it does not exist. Which is very strange because even though it isn't possible to locate tangibly in the body, it is felt, it is real and it is definitely “there”.
Technically, pain is a sensation that we have an experience of and it is woven into our physical, psychological, behavioural and interpersonal lives.
In an earlier blog I wrote about approaching pain like approaching the assembly of some furniture from IKEA and suggested that understanding more about how pain is created and what pain is (and is influenced by) is an important part in recovery from chronic symptoms.
In order to understand a bit more about pain, it's necessary to take a little peek under our skin at the human nervous system aka this guy/gal ⤵️
The basic function of the nervous system is to keep you alive. To do that it must take information in from the body and external world, process it, predict what might happen and respond as it deems most appropriate.
Input > Processing > Prediction > Response
Nociception - nociwhaaat?
To understand how the nervous system gathers information from the body when it comes to pain, we must start with a little bit of neurological talk - specifically a thing called “nociception”.
Please don't let this word scare you off from reading - everything will be explained simply so that you understand this easily.
Nociception is the process by which information about actual tissue damage (or the potential for damage) is relayed to the brain.
“Noci” - comes from “nocero”, which is Latin for “to harm/injure”
“Ception” - to make sense of, to understand or inquire more deeply about
“Nociception” is therefore the process by which the brain understands or makes sense of the signals / information it receives from the body about tissue harm or the potential for tissue harm.
To make this more practically understandable here is a simple example:
I roll my ankle when I step down off a curb and begin to feel pain. How is nociception involved here?
It is likely that the little nerve endings (called nociceptors) that are embedded in the tissues around my ankle are stimulated much more than normal by the forces that pass through my ankle when I roll it.
This stimulation of these nociceptors is transmitted up through the nerves in my leg into the spinal cord where it begins to be processed and responded to or is sent up into the brain for further processing.
When I roll my ankle, it's possible that I injure or have the potential to injure the tissues. Therefore my nociceptive system is likely to get stimulated more than normal.
Nociception itself is not pain - it is the message from the body to the brain about the tissues of the body. The brain then does all sorts of awesome complicated processing and decides whether pain is an appropriate response to have.
With me so far?
Short recap: the nociceptive system informs the brain about harm to the tissues or potential harm to the tissues. Nociception is not pain. It is however often closely related to a pain experience.
In the older eras of the understanding about pain, nociception was thought of as a direct cause of pain but more recently that has be found not to be true. Think for example of being in a car accident where you are badly injured. Clearly there will be very heightened nociceptive activity happening due to the injuries sustained - but often the person does not feel pain at the time because there is adrenaline flowing and a more urgent need to get to safety - they often feel it afterwards when they are in the hospital. In that example, nociception is happening, but these nociceptive messages are “not listened to” by the brain and pain is not present.
In the example above, when nociceptors get activated by rolling my ankle, the amount of information they send up to the spinal cord is dependent on a few things - such as inflammation and immune responses.
It is normal for much more signalling to the brain to happen (more messages to the brain) when there is inflammation present. Inflammation “excites” or increases the stimulation of nerve endings like nociceptors. If they signal more intensely, it is more likely that I will experience pain.
We can safely say that inflammation increases the intensity of the pain you feel because it causes the spinal cord and brain to be bombarded with many more messages and much stronger messages than if there were no inflammation present. This is a major part of the reason that tissue injuries hurt - because inflammation is part of the healing process.
Cross-communication
When the signalling of the nociceptors reaches the spinal cord, it is often sent further up into the brain itself for processing. The first place the information reaches is usually a brain area called the thalamus. To keep it simple, think of the thalamus like Grand Central Station in New York or Euston Station in London. A place where many connecting train lines meet and you can travel anywhere. The thalamus is a major connection hub in the brain.
From here many different brain areas are communicated with and involved in the processing of the nociceptive signal from my ankle including the memory centres, the threat processing centres and the autonomic nervous system centres.
Based on all of this cross-communication, the brain will make a perception about what has just happened to my ankle.
Some of that cross-communication may involve brain centres that can act to dampen down the nociceptive signalling - meaning the brain can turn the volume down on the messages it is receiving from the body about my ankle. This is the descending inhibition system. (We will deal with this in a separate blog - this one is long enough as it is😅)
That perception is influenced by many things (including the psychological, emotional & behavioural side of life) and will then result in me experiencing ankle pain or protective muscle tone or other types of responses such as stress hormone release or changes in my heart rate or blood pressure.
To recap: I roll my ankle which stimulates my nociceptive system. This nociceptive information is sent to the spinal cord and then into the brain to the thalamus which communicates with many other brain areas to form a perception about what has happened to my ankle. That perception may result in pain, protective muscle tone or other autonomic responses.
In this blog we have described a significantly simplified version of the biological reactions that happen in our bodies and contribute towards the creation of pain. I hope it helps you to understand a little more about what happens in the body to create pain.
*** Please note that in the example above (rolling the ankle), actual tissue injury is not needed for my nervous system to perceive that I need protection. The potential for injury / harm is all that is needed. As we get into more of the writing I have planned for this Substack, we should begin to see how pain can be present, even when injury is not! ***
If we were to explore in further depth, it is likely that the more technical and scientific information needed to explain more about pain would cause this blog to wander into the realm of “I have no context through which to understand this” for almost every normal person in pain. And that makes it in-accessible and not useful!
In Part 2, we will begin to explore how the psychological side of life influences and relates to pain.
Got a question or comment about this blog? Write it below and I will get back to you as soon as I have a chance.
I’d love it if you would share this with anyone that is struggling with pain and would benefit from reading a little more about it.
David
P.S > this blog is a sister project to my online course and membership site -Move Out Of Pain, where I've built out everything you need to stop pain limiting how you live your life. Follow a structured plan that helps you to get clear, reduce fear, improve your movement, strength and confidence and address all the other influences on your symptoms.