What Is Central Sensitisation, and Why Does Pain Persist?
Central sensitisation is a state in which the nervous system itself amplifies pain signals, so you feel more pain than the level of tissue damage would normally cause. It helps explain why chronic pain can persist long after an injury has healed, and why scans sometimes look normal even though the pain is very real.
Key takeaways
- Central sensitisation means your nervous system has become more sensitive to pain signals.
- Pain without obvious tissue damage is not imagined. It is a real, measurable change in how your brain and spinal cord process signals.
- Scans and blood tests often look normal because the problem is in signal processing, not in damaged structures.
- Sleep, stress, movement and education all play a role in turning the sensitivity up or down.
- Recovery is possible, usually through a combination of approaches rather than a single treatment.
What does central sensitisation actually mean?
Central sensitisation is a change in the way your central nervous system, your brain and spinal cord, processes incoming signals from the body. Normally, your nervous system acts like a volume dial. When tissue is injured, it turns the volume up so you notice the pain and protect the area. That is helpful in the short term.
With central sensitisation, the volume dial gets stuck on high. Signals that should feel mild, or even signals that are not painful at all, get amplified. The result is pain that is out of proportion to what is happening in the tissues, or pain that continues long after the original injury has healed.
Two terms often come up alongside central sensitisation. Hyperalgesia means something that would normally be a little painful feels much more painful. Allodynia means something that should not hurt at all, like light touch or a gentle breeze on the skin, is felt as pain. Both are signs that the nervous system's sensitivity has been turned up.
How do you know if your nervous system is sensitised?
There is no single blood test or scan that diagnoses central sensitisation. Clinicians recognise it from a pattern of features. You may notice some of the following.
The original problem has healed, but the pain carries on for months or years.
What started in one area now affects a wider region or seems to move around.
Clothing, bedsheets or gentle pressure feel uncomfortable or painful.
X-rays, MRI or blood tests come back largely normal, yet the pain is very much there.
Other common features include poor sleep, fatigue, brain fog, heightened sensitivity to noise or bright light, and mood changes. These are not separate conditions. They are part of the same nervous system picture.
A note on red flags. If you develop sudden numbness, weakness, loss of bladder or bowel control, or any abrupt severe symptoms, these need urgent medical attention. Contact your GP, call 111, or go to A&E. Central sensitisation does not cause these symptoms.
Why does chronic pain persist even when nothing is damaged?
Chronic pain persists because the nervous system has learned to stay in a protective state. Once central sensitisation develops, the brain and spinal cord keep producing pain signals even without ongoing tissue damage. Pain becomes less about what is happening in your joints or muscles, and more about how your nervous system is interpreting signals.
Ongoing pain signals over weeks or months can physically change how nerve cells in the spinal cord behave.
Emotional stress activates the same brain regions involved in pain. High stress keeps the system on alert.
Sleep is when the nervous system recalibrates. Poor sleep keeps pain sensitivity high, which then disrupts sleep further.
Protecting the painful area by moving less can actually reinforce the nervous system's belief that movement is dangerous.
This does not mean the pain is imagined or "all in your head." The changes in central sensitisation are measurable in research settings. Your pain is real. It is just being driven more by nervous system sensitivity than by structural damage.
Can a scan show central sensitisation?
No. No current clinical scan, whether X-ray, MRI, CT or EOS, can show central sensitisation. That is because the problem is in how signals are processed, not in the structure of your bones, joints or soft tissues.
This is an important point. Many people with chronic pain have had multiple scans that look normal, and they are left feeling frustrated or unbelieved. A normal scan does not mean there is nothing wrong. It means the source of the pain is not a structural problem that imaging can detect.
When imaging is helpful. Imaging, including standing whole-body scans like those offered at ScanAlign, is valuable when there may be a structural or alignment problem contributing to pain. If your clinician suspects a mechanical issue alongside sensitisation, imaging can help rule that in or out. But if central sensitisation is the main driver, the priority is usually a pain-informed clinical assessment and a management plan rather than more scans. If you are unsure, you can speak to us about whether imaging would help in your situation.
It is also worth knowing that scan findings and pain do not always match. Many people with visible changes on a scan, such as disc bulges or mild arthritis, have no pain at all. And many people in significant pain have scans that look entirely normal. This mismatch is exactly what you would expect when central sensitisation is involved.
What helps when pain is driven by nervous system sensitivity?
Recovery from central sensitisation is possible, but it usually involves a combination of approaches rather than a single fix. The goal is to gradually turn down the nervous system's sensitivity. Here are some of the areas that evidence supports.
Understanding why your pain persists can itself reduce threat perception. Knowledge is a genuine pain-relief tool.
Gradually increasing activity teaches the nervous system that movement is safe. This is not about pushing through pain, but pacing carefully.
Improving sleep quality and managing stress can lower the nervous system's baseline sensitivity over time.
A team approach, combining physiotherapy, psychology and medical input, often works better than any single treatment alone.
It is worth saying clearly: there is no quick fix. But many people do improve, sometimes significantly, once they understand what is driving their pain and take a consistent, step-by-step approach. For more on when structural factors may also be playing a role alongside sensitisation, see our back pain clinic page.
Frequently asked questions about central sensitisation
They overlap but are not identical. Central sensitisation is a mechanism, a way the nervous system behaves. Fibromyalgia is a diagnosis that describes widespread pain and other symptoms. Central sensitisation is thought to be one of the main processes behind fibromyalgia, but it can also occur in conditions like chronic back pain, osteoarthritis and persistent post-surgical pain.
No. The pain is completely real. Central sensitisation involves measurable changes in how the spinal cord and brain process signals. It is not imagined, exaggerated or psychological in the dismissive sense. It is a genuine alteration in nervous system function.
No. Standard clinical imaging cannot show central sensitisation. Scans look at structure, not at how the nervous system processes signals. A normal scan result is common in people with central sensitisation and does not mean there is nothing wrong.
It is diagnosed clinically by a healthcare professional who recognises the pattern: persistent pain, heightened sensitivity, pain that spreads beyond the original area, and normal or disproportionate scan findings. Questionnaires such as the Central Sensitisation Inventory can help, but there is no single definitive test.
Yes, in many cases. The nervous system can learn to turn the sensitivity back down. This usually takes time and involves a combination of pain education, graded movement, better sleep, stress management and sometimes medication. It is not a quick process, but meaningful improvement is achievable for many people.
Usually, more scans are not helpful when central sensitisation is the main issue, because the problem does not show up on imaging. However, if there is a specific clinical question about a possible structural or alignment problem, imaging may still be useful. A clinician can help you decide.
Peripheral sensitisation happens locally, at the site of an injury, where nerve endings become more sensitive. This is normal and usually settles as healing occurs. Central sensitisation happens higher up, in the spinal cord and brain, and can continue independently of any ongoing tissue damage.
Yes. Stress activates the same brain areas involved in processing pain and keeps the nervous system on high alert. This does not mean the pain is caused by stress. It means stress is one of several factors that can turn the pain volume up. Reducing stress can help turn it down.
Yes, when done gradually. Graded exposure to movement teaches the nervous system that physical activity is safe. The key is starting gently and building up slowly, not pushing through severe pain. A physiotherapist experienced in persistent pain can guide this process.
A good starting point is your GP, who can refer you to a pain specialist, a pain-informed physiotherapist, or a multidisciplinary pain clinic. These professionals understand the nervous system's role in persistent pain and can offer a coordinated approach to management.
Not sure if imaging is right for you?
If you are living with persistent pain and wondering whether a structural or alignment issue might be part of the picture, we are happy to talk it through. Our consultations are free, with no obligation and no pressure.
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- Woolf CJ. Central sensitization: implications for the diagnosis and treatment of pain. Pain. 2011;152(3 Suppl):S2-S15.
- Nijs J, et al. Applying modern pain neuroscience in clinical practice: criteria for the classification of central sensitization pain. Pain Physician. 2014;17(5):447-457.
- NHS England. Chronic pain overview. nhs.uk/live-well/pain
Written by Abbas Dhami (Specialist Diagnostic Radiographer)
This page is general information and not a diagnosis.
ScanAlign is the trading name of CoreMed Solutions Ltd and operates under The Harley Street Hospital's CQC licence.