Why did my back go into spasm?
The spasm is not the problem. It's the response to a problem. Something persuaded your nervous system that your spine was unsafe, and until you know what, you're waiting for the next episode.
What follows is not a diagnostic test and it can't replace an examination. It's the six patterns I've seen most often over twenty years, written so you can recognise which conversation to have with a clinician — and so you stop doing the thing that keeps setting it off.
Some of these overlap. Plenty of people have two at once. If you read one and think that's me, that's a useful starting point, not a conclusion.
- Sciatica and nerve irritation Pain that travels into the buttock or down the leg, with the low back locking to protect the nerve root.
- Disc bulge or herniation Pain that spikes with bending, sitting and coughing, and a back that locks the moment you move the wrong way.
- Spinal stenosis Legs that ache or go heavy when you stand and walk, and ease the moment you sit or lean forward.
- Facet joint irritation A sharp local catch on arching, twisting or standing up, with pain that stays close to the spine.
- SI joint irritation Pain in one dimple of the low back or deep in the buttock, worse on stairs, standing on one leg, and rolling over in bed.
- Overload, fatigue and stress The episode with no dramatic cause — a sneeze, a sock, the third bad night of sleep in a stressful month.
A rough way to tell them apart
Three questions get you surprisingly far.
- Does it go below the knee? If yes, a nerve is likely involved — look at sciatica, disc or stenosis. If it stays local or reaches the buttock, look at facet, SI joint or load.
- Bending forward or arching back — which is worse? Forward bending and sitting point towards a disc. Arching and standing point towards facet joints or stenosis.
- Is it one side, at one point you can cover with a finger? That's more typical of the SI joint than of anything else on this list.
None of that is diagnosis. It's orientation — enough to walk into an appointment able to describe your pattern instead of just saying it hurts.
Get the emergency protocol
What to do in the first 48 hours, the day-by-day recovery through to day ten, and how to come back without setting it off again. 21 pages, free.
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