WHY CHRONIC PAIN CAN PERSIST: UNDERSTANDING CENTRAL SENSITISATION

If you’re dealing with ongoing pain that doesn’t seem to match any clear injury or diagnosis, it can feel frustrating (especially when it’s hard to explain). But there’s a known reason this can happen. For some people, the nervous system becomes overly sensitive, continuing to send out pain signals even when the original injury has settled.

This process is called central sensitisation. In this blog, we’ll explore what it means, how it might be showing up in your body, and how a personalised approach can help calm things down and get you moving forward again.

What is central sensitisation?

Central sensitisation is a term used to describe what happens when the nervous system becomes oversensitive, almost like an alarm system that’s stuck on high alert. It’s one of the key reasons why chronic pain can continue, even when there’s no longer any active injury or inflammation in the body.

How central sensitisation and chronic pain are linked

In a healthy system, pain signals travel from the body to the brain when there’s a problem (like a twisted ankle or a cut). But with central sensitisation, this process gets turned up too high. The brain starts to interpret normal sensations—even gentle touch, movement, or mild pressure—as painful. In some cases, the pain can also spread beyond the original area or become more intense than expected. This is why central sensitisation and chronic pain often go hand in hand.

What changes in the nervous system?

This change happens in the central nervous system, which includes the brain and spinal cord. Over time, the nerve pathways involved in processing pain become more easily triggered, meaning that the threshold for what causes discomfort gets lower. This can lead to persistent pain, heightened sensitivity, and symptoms that feel out of proportion to what’s actually going on in the body.

Signs that central sensitisation could be at play

Central sensitisation doesn’t look the same for everyone, but there are some common signs that can suggest your nervous system might be more sensitive than it should be.

You might notice:

• Pain that feels out of proportion to what’s going on in your body
• Pain that lingers long after an injury has healed
• Pain that spreads beyond the original area
• Pain from things that shouldn’t hurt (this is called allodynia), such as light touch, wearing certain clothes, or gentle movement 
• An exaggerated response to pain. For example, a small bump may feel unbearable (known as hyperalgesia)
• Heightened sensitivity to light, sound, temperature, or stress
• Fatigue, brain fog, poor sleep, or difficulty concentrating

If this sounds familiar, it doesn’t mean something is “wrong” with you. It may simply mean your nervous system has become more reactive over time, and it can be retrained with the right support.

While the pain might not show up on a scan, that doesn’t make it any less real. These changes in the nervous system are well-documented in research and help explain why chronic pain can feel so intense, even without visible damage.

What the science says about central sensitisation and chronic pain

Central sensitisation is now widely accepted in pain science as a major factor in many chronic pain conditions. Research published in The Lancet Rheumatology (1) and The Cleveland Clinic Journal of Medicine (2) shows that this mechanism, also known as nociplastic pain, is involved in conditions such as:

• Fibromyalgia
• Irritable bowel syndrome (IBS)
• Migraine and tension-type headaches
• Chronic low back pain
• Rheumatoid and osteoarthritis
• Ehlers-Danlos syndrome (EDS)
• Complex regional pain syndrome (CRPS)

These studies describe structural, chemical, and functional changes in the CNS, including:

• Heightened neuron excitability
• Lower thresholds for pain activation
• Altered synaptic transmission
• Ongoing pain amplification with minimal input from the body

Nijs et al. (2021) notes that features of central sensitisation predict poor treatment outcomes in certain patients — unless the pain processing system itself is addressed. This understanding has led to a shift in treatment from “fixing” tissues to retraining the nervous system.

Recent research has also shown that targeting the nervous system directly can lead not just to symptom improvement, but meaningful pain recovery. A randomised controlled trial published in JAMA Psychiatry (3) by Ashar et al. (2022) compared pain reprocessing therapy (PRT) with placebo and usual care in people with primary chronic low back pain. The study found large reductions in pain intensity in the PRT group, with many participants becoming pain-free or nearly pain-free.

Importantly, these improvements were sustained at one-year follow-up. The researchers also identified that changes in participants’ beliefs about pain, particularly shifting away from the idea that pain always signals tissue damage, played a key role in recovery. This supports the growing understanding that retraining how the brain interprets pain signals can be a powerful pathway to long-term change. 

Calming the system: How recovery begins

The good news is that your nervous system can change, and this change can be an important part of recovery. Just as the brain and spinal cord can become sensitised, they can also be retrained to become less reactive over time. Although this process doesn’t happen overnight, with the right support and approach, meaningful recovery is absolutely possible.

At Integrity Physiotherapy, we work with people every day who are navigating chronic pain and central sensitisation. Our multidisciplinary approach is all about helping you feel safe in your body again and giving your nervous system the chance to settle.

Some of the approaches that may be used include:

• Pain education – Understanding how pain works can reduce fear, increase confidence, and give you back a sense of control.
• Graded movement and pacing – We’ll guide you through gentle, structured movement that builds up gradually and safely.
• Somatic tracking and brain-based practices – These methods help rewire how your brain responds to pain, using focused awareness and attention-shifting techniques.
• Mind-body therapies – We often incorporate approaches such as PRT, mindfulness, and breathwork to support the nervous system from the top down.

Rather than aiming for lifelong management, the goal is recovery. These approaches work not by “fixing” something broken in the body, but by changing how your nervous system interprets signals.

You don’t have to figure it out alone

If you’ve been living with persistent pain that doesn’t make sense on scans, you’re not imagining it. Central sensitisation is a recognised mechanism that helps explain why pain can continue even after healing.

More importantly, it means recovery is possible.

At Integrity Physiotherapy, we support people across Perth and Australia through physiotherapy for chronic pain. Our evidence-based approach focuses on calming the nervous system, rebuilding confidence, and guiding you toward real change

References

1. Nijs, Jo, Steven Z. George, Daniel J. Clauw, César Fernández-de-las-Peñas, Eva Kosek, Kelly Ickmans, Josué Fernández-Carnero, Andrea Polli, Eleni Kapreli, Eva Huysmans, Antonio I. Cuesta-Vargas, Ramakrishnan Mani, Mari Lundberg, Laurence Leysen, David Rice, Michele Sterling, and Michele Curatolo. 2021. “Central Sensitisation in Chronic Pain Conditions: Latest Discoveries and Their Potential for Precision Medicine.” The Lancet Rheumatology 3 (5): e383–92. https://doi.org/10.1016/S2665-9913(21)00032-1
2. Volcheck, Mary M., Stephanie M. Graham, Kevin C. Fleming, Arya B. Mohabbat, and Connie A. Luedtke. 2023. “Central Sensitization, Chronic Pain, and Other Symptoms: Better Understanding, Better Management.” Cleveland Clinic Journal of Medicine 90 (4): 245–54. https://doi.org/10.3949/ccjm.90a.22019
3. Ashar, Yoni K., et al. 2022. “Effect of Pain Reprocessing Therapy vs Placebo and Usual Care for Patients With Chronic Back Pain: A Randomized Clinical Trial.” JAMA Psychiatry 79 (1): 13–23. https://doi.org/10.1001/jamapsychiatry.2021.2669