(The following is the transcription of the video above)

It is generally accepted in the branch of pain medicine that there are four types of pain: nociceptive, inflammatory, neuropathic and dysfunctional (1-3). The first three have been discussed in previous videos and in this video we'll discuss about dysfunctional.

Dysfunctional pain is tricky to define AND to understand, some will even say that it does not exist. Regardless, let's start with the definition of dysfunctional pain: dysfunctional pain is pain experienced when there is an error in pain processing ability of the body.

This means that there's likely to be NOTHING that's structurally wrong with the patient; X-ray will be normal, MRI will be normal, blood test will be normal, and your muscles and joints and fine. And you might be thinking “hang on a sec, how can you have pain without something wrong with me?"

Well I'm not saying that there is NOTHING wrong with you; it's just that where it's gone wrong is not something that can be SEEN. And THAT is the pain processing centres of the body.

I'll give you an example. Let's say that you've just cut yourself on your finger, it hurts right? I'm sure you can remember that searing pain that is when you've just cut yourself. And that's perfectly normal to feel pain. Now, how long does it take for that initial pain to settle? Maybe ten minutes? Thirty if it's particularly bad.

So when the pain has settled after ten minutes or so, does that mean that your cut has been healed? Not at all, it might take at least a day to really heal up.

So, why does your pain reduce so significantly so quickly, unrelated to actual healing? There are a number of reasons for this but one of the major ones is our pain processing centres. They go - "oh look, a cut on my finger. It's just a cut. I'm sure it'll be fine". Then turn down the initial spike of pain pretty quickly. And this all happens without you being quite aware.

But what if that "turning down the pain" by the pain processing centres does NOT occur? The pain will persist, quite unreasonably, even well after the cut is healed. That's dysfunctional pain. Pain that persists because of errors in our pain processing ability.

Sometimes this occurs even without a particular injury per se. In fact it's most common that this unreasonable persistence of pain occurs from gradual build up rather than one-off trauma. Think chronic back and neck pain, shoulder pain, tennis elbow, most overuse injuries, headaches, irritable bowel syndrome, fibromyalgia, the tension that you feel when you're anxious or stressed, the list goes on.

For now, the most crucial thing for you to understand is the very existence of dysfunctional pain, how it can manifest without any visible structural abnormalities, and how common it actually is.

In summary, there are four types of pain: nociceptive, inflammatory, neuropathic and dysfunctional. What does that mean in real life and how do we apply this concept? That is a pretty big question, and I'll try to explain it some degree in the next video.

References

1. Costigan M, Scholz J, Woolf CJ. Neuropathic pain: a maladaptive response of the nervous system to damage. Annu Rev Neurosci. 2009;32:1-32.

2. Vardeh D, Mannion RJ, Woolf CJ. Toward a Mechanism-Based Approach to Pain Diagnosis. J Pain. 2016;17(9 Suppl):T50-69.

3. Woolf CJ. Pain: Moving from Symptom Control toward Mechanism-Specific Pharmacologic Management. Annals of Internal Medicine. 2004;140:441-51.