Why Does My Back Still Hurt When My MRI Looks Normal?
Chronic low back pain with a clean MRI is common. Here's what the research says about why — and what actually helps.
Dr. Pierre Zook, PT, DPT, OCS and Janae Zook, BSN, RN
Est. Read time ~3 to 4 minutes
If you've lived with low back pain for months or years, you've probably heard some version of “your scans look fine.” It's meant to be reassuring. It often lands the opposite way.
Here's the short version: your scan shows tissue. Pain isn't made of tissue alone.
A clean scan isn't the whole story
Researchers reviewed 33 imaging studies covering 3,110 people with no back pain at all (Brinjikji et al., 2015). Among those pain-free adults, 37% of 20-year-olds already showed disc degeneration. By age 80, 96% did. Disc bulges followed the same curve — 30% at 20, 84% at 80.
Findings show up in people who feel fine. And people in real pain often scan clean.
That's not a reason to distrust imaging. It's a reason not to ask it a question it can't answer. A scan is very good at showing structure. It was never designed to show how much something hurts.
When the nervous system turns up the volume
The International Association for the Study of Pain built a category for exactly this situation. In the ICD-11 classification, chronic primary pain is diagnosed when pain has persisted more than three months and is tied to real emotional distress or loss of function — and the diagnosis is “appropriate independently of identified biological or psychological contributors unless another diagnosis would better account for the presenting symptoms” (Nicholas et al., 2019).
In other words, a clean scan doesn't rule it out. It isn't a shrug. It's a category.
One process behind it is central sensitization — a change in how the spinal cord and brain process pain signals, separate from whatever started the pain. Think of it as a volume knob that got turned up and stayed there. Estimates of how common it is vary widely and lean on questionnaires rather than a definitive test, but one systematic review put the average at just under half of chronic low back pain cases (Schuttert et al., 2021).
What researchers found when they never touched anyone's back
A study published in Scientific Reports in January 2026 tested this directly (de la Coba et al.). Researchers compared 40 adults with chronic low back pain, recruited from a hospital rehabilitation service in Jaén, Spain, to 40 adults with no pain.
They never touched anyone's back. Instead they pressed on a fingernail — nine times, five seconds each, about half a minute apart, at a pressure calibrated to each person so the first press registered as mildly painful for everyone. Both groups rated that first press about the same.
Then the groups split. For the pain-free adults, the sensation faded — by the ninth press it bothered them less than the first, which is what a healthy nervous system does with a repeated, harmless signal. For the adults with chronic back pain, it climbed. Same pressure, same finger.
Nowhere near the spine. Two different responses.
It isn't a clean diagnostic test on its own — the pattern sorted the two groups correctly about two-thirds of the time, and it tracked group membership rather than symptom severity. But it was the only pain-sensitivity measure in the study that separated the groups at all; the standard pressure-pain threshold, tolerance, and temporal-summation tests all came in at roughly chance. It's also one study, 40 people per group, all between 40 and 65. What it shows is that a measurable nervous-system process can keep pain going long after tissue has healed.
What actually helps a sensitized nervous system
A nervous system that learned to amplify pain can also learn to settle back down. Usually gradually. Rarely through rest alone.
Sleep does more work here than most people expect. A review of the prospective research found that sleep problems reliably predicted new episodes and flare-ups of chronic pain — and were a stronger predictor of pain than pain was of sleep (Finan et al., 2013). A rough night can make old pain feel worse for no new reason. More on that in Sleep: The Most Underrated Factor for Injury Prevention and Recovery.
Movement is the other half. Not rest — movement, at a dose your system can handle today. A graded return to activity gives your nervous system repeated evidence that loading your back is safe. We cover the why in Movement Is Medicine: How Staying Active Helps You Heal Faster and Prevent Pain.
Where to start:
✔ Consistent sleep and wake times
✔ Movement most days, not perfect days
✔ Small increases, not big jumps
✔ Flare-ups managed, not feared
✔ A plan you can actually repeat
None of this means the pain is “in your head.” It means your body has more of a say in this than a single image can capture.
The Trek perspective
This is exactly why we don't stop at the injury. Chronic pain is rarely one thing — it's tissue, movement patterns, sleep, stress, and how your nervous system has adapted, all at once. Instead of guessing, we measure, and we build the plan around the whole picture.
If you've been told your pain “shouldn't” still be there, we'd like to help you understand why it might be — and what to do about it.
Schedule an evaluation with Trek Physical Therapy in McMinnville, OR.
Sources
Brinjikji, W. et al. “Systematic literature review of imaging features of spinal degeneration in asymptomatic populations.” American Journal of Neuroradiology, 36(4), 811–816 (2015).
Nicholas, M. et al. “The IASP classification of chronic pain for ICD-11: Chronic primary pain.” Pain, 160(1), 28–37 (2019).
Schuttert, I. et al. “The definition, assessment, and prevalence of (human assumed) central sensitisation in patients with chronic low back pain: A systematic review.” Journal of Clinical Medicine, 10(24), 5931 (2021).
de la Coba, P., Garcia-Hernandez, A., Aranda-Villalobos, P., Andrade-Ortega, J. A., & Reyes del Paso, G. A. “Assessment of central pain sensitization in chronic low back pain and its utility in diagnosis and prediction of clinical severity.” Scientific Reports, 16, 3540 (2026).
Finan, P. H., Goodin, B. R., & Smith, M. T. “The association of sleep and pain: An update and a path forward.” The Journal of Pain, 14(12), 1539–1552 (2013).
