They are two different things, and confusing them is why so many people live for years afraid to move because of an image.
When the disc really is irritating the nerve root, the picture has a recognisable shape — in the lower back, the pain travels down the leg; in the neck, down the arm. And it is not the scan that reveals it: it is how your body responds to movement.
The logic is the same in both regions — what changes is the path. This set is what I usually see when the herniated disc really is irritating the nerve root, and it is not there for you to diagnose yourself.
From a review on back pain published in 2026 in the medical journal JAMA. The same review shows that 74.4% of people with no pain at all have changes on MRI.
Because the disc changes with age in everyone, with pain or without. A disc protrusion or a herniation on a scan tells you there is a change in that disc — it does not tell you that it is where what you feel comes from.
What changes everything is knowing whether, right now, that herniated disc is compressing or irritating the nerve root. And that is not read in an image taken with the person lying down and still: it is read in the exact path of the pain, in the response to repeated movements, in nerve tension tests, and in the strength and sensation of the limb.
There is one sign that always makes me distrust the label: someone diagnosed with a herniated disc — in the lower back or the neck — who carries on training normally and only has pain in one specific movement. In that case, it is almost certainly not the herniated disc that is driving the picture.
This condition behaves in its own way, quite differently from ordinary back pain.
The head held forward of the body for a long time is by far the most repeated complaint in this condition.
Looking over your shoulder while driving, or turning to talk to someone beside you, can shoot the pain down the arm.
Looking up, having your hair washed at a basin, or being in the dentist's chair. It closes the space the nerve root comes out of.
Waking with your arm tingling, and the pain worsening in the early hours to the point of not getting back to sleep. It is one of the signs that most makes me think of this condition.
A shopping bag, a suitcase, a child in your arms. The weight increases the traction on the already irritated root.
Just as in the lower back, it increases the pressure inside the canal and can shoot the pain down the arm.
Many people discover this on their own without knowing why: raising the arm and resting the hand on the head reduces the tension on the root and eases it. It is one of the most characteristic signs of this condition.
Holding your elbow with the other hand, or resting the arm on a pillow, takes the weight off it and usually settles the symptoms.
Neither high nor low: the one that keeps your neck in line with the rest of your spine. It usually makes more difference than you would expect.
There are positions and movements of the neck that increase the space the root comes out of. Finding which is yours is one of the first aims of the assessment.
Getting up and moving your neck every half hour is worth more than any perfect posture held for hours.
Exactly the same applies here as in the lower back: once the direction that eases it is found, movement becomes part of the solution.
The pain of a herniated disc usually travels along a continuous path — from the lower back to the toes, or from the neck to the fingertips. The further down it goes, the more irritated the nerve root is. Going past the knee, or past the elbow, is the threshold that makes me take the case more seriously.
So the first aim of treatment is to make that pain stop travelling towards the foot or the hand, and start moving closer to the spine, up above the knee or the elbow. This is called centralisation, and it is the most positive sign that things are going the right way.
And I explain this to you before we start, deliberately: centralisation often happens before the pain drops in intensity, and it may even come with more discomfort near the spine. Without that warning, it is easy to read that as getting worse — and to abandon precisely the direction that was working.
The height of the bar is how far down the pain goes. Going up means improving, even if it still hurts.
Almost everyone who arrives here with this diagnosis believes that moving will push the disc further out. They have often heard that from someone — sometimes from a healthcare professional, said with the best of intentions.
The effect of that sentence is always the same: the person stops moving, loses strength, loses confidence, and the condition settles in. Sentences like "you must not bend your back" or "if you bend, the disc will burst" do more damage than the movement they forbid.
An important part of what I do in the treatment room is showing you, right there, in a safe and controlled setting, that there is movement you can do without risk. Seeing it with your own body is worth more than any explanation of mine.
We test positions and movements that reduce the tension on the nerve root. When the right one is found, the relief is recognisable — and it becomes the tool you take home.
Progressively and under control, to rebuild the confidence to move. This is where the strength and capacity lost during the weeks of stillness get recovered.
There are cases that benefit from medical care alongside this, and cases where surgery is indicated. Recognising that in time is part of my job — and I tell you when it happens.
That disc changes appear in a large proportion of people with no pain at all; that pain caused by a compressed nerve is a minority of cases; and that routine imaging is not recommended for most back pain. All of this comes from a review published in 2026 in the medical journal JAMA.
The pattern of signs described on this page and the way I interpret the response to movement come from my training and my practice. They describe what I observe; they are not a guaranteed outcome nor a prediction about your case. I always tell you which of the two you are hearing.
If yours is not here, ask me directly.
Most people with this condition never reach surgery — but I cannot guarantee you anything about your case before assessing you, and nobody should. What I can tell you is that there are clear criteria for when surgery becomes the right option, and that if I find any of them I tell you and point you the way, instead of carrying on treating out of stubbornness.
That is not how the disc works, and the idea does more damage than the movement it forbids. What is true is that there are directions of movement that, at this stage, make your symptoms worse, and others that ease them. The work is to find which are yours — not to stop moving.
The disc does not "go back into place" like slotting a part in. What changes, and this is what matters, is the irritation of the nerve root: with time and the right stimulus, symptoms often reduce even when the image stays the same. It is another reason not to measure your progress by repeated scans.
Almost never. The image changes far more slowly than the symptoms, and repeating it without clinical indication usually adds worry without changing anything in the treatment. What guides the next step is always the same: what you can do, how far down the pain goes, and how you respond to the movement tests.
Nothing on this page replaces an assessment by a healthcare professional. And there are situations that are not a matter for physiotherapy at all:
this calls for urgent medical care, the same day.
A medical appointment the same day, as soon as possible, with neurosurgery or spinal orthopaedics.
This is not a matter for physiotherapy, nor for any other healthcare professional.
And it is not a matter of waiting to see whether it improves. Here, time is what weighs most on the outcome: the sooner you are seen by a doctor, the better.
See every sign, by area, and what to do in each caseTwo lines is enough. I answer, and I tell you frankly what I think — including whether I believe your case needs to be seen by a doctor first.
Initial conversation free of charge. I always reply — and, most of the time, the same day.
Cashin AG et al. Review on non-specific low back pain. JAMA, 2026. — the proportion of non-specific low back pain and of radiculopathy/stenosis among those seeking care; degenerative changes on MRI in people without low back pain (74.4%) and with pain (77.8%); recommendations on the use of imaging; the effectiveness of exercise in chronic low back pain and of invasive treatments.
Brinjikji W et al. Systematic literature review of imaging features of spinal degeneration in asymptomatic populations. AJNR American Journal of Neuroradiology. 2015;36(4):811-816. — the prevalence of degenerative findings in people without symptoms, by age group.
A synthesis of the literature on pain myths and beliefs (Melzack 1999; Moseley 2003; Seki & Ouchi 2020) — the weak correlation between pain and structural changes on imaging, across several regions of the body.
Anything on this page that does not point to these references is my own clinical reading, marked as such throughout the text. No information here replaces an individual assessment.