Why is your back pain or sciatica sensitive to temperature (and humidity) changes?  I love this sort of question, because there’s a scientific answer – and if you know me, you know I love a bit of sciencey stuff.  I also like diagrams, but I honestly couldn’t find one that wasn’t overly complex AND made it clearer than my words.  So, I included this image because it reflects my schoolboy experiences of science, and I’ve always wanted to have a reason to use it.  I’m hoping I can explain this with the power of the written word alone!

Neurones (sciencey word for a nerve fibre) have a baseline (resting) level of electrical activity in them.  When a neurone fires repeatedly – as often happens when you experience painful sensations – that neurone “re-sets” its level of resting electrical activity at a higher level.  When a neurone “fires”, it sends an impulse to the next neurone in the chain – and all sensory neurone “roads” lead to not Rome, but to your brain.  If the neurone has a higher resting level of electrical activity it can be caused to “fire” by stimuli that woulnd’t normally trigger it e.g. modest changes in temperature.  Think of it like having a car alarm that goes off when someone walks past the car instead of only when someone tries to steal it!

This is one of the mechanisms at play in “sensitisation”, which I blogged about recently.  If I’ve done a rubbish job of explaining this, or if you’d like more info on this or any other aspect of your recurring back pain/sciatica, just post in the comments or email me directly.