How does pain become chronic pain?

May 23rd, 2019 | by Jake Cooke | Posted in Pain

If you’ve ever hit your thumb with a hammer you’ll know just how hypersensitive it can feel over the next few days. The term for that pain is ‘hyperalgesia’. It occurs in all injured or inflammed tissue, meaning it can occur with a muscle strain, a joint sprain or with trauma. Even if you have a high pain threshold you might start to complain about the lightest touch.

What is hyperalgesia?

Hyperalgesia is the heightened sensitivity to pain. We can divide it further into primary and secondary hyperalgesia. Primary occurs to all injured or inflammed tissue. However, secondary can occur in perfectly healthy tissue. It occurs due to central sensitisation, a change in the way your nervous system processes pain. With central sensitisation there is an increase in pain promotion and a decrease in pain inhibition. This is an important part of chronic pain.

Even tissue far from the site of injury can become hypersensitive. For example, if you’re suffering from chronic right shoulder pain you might develop hyperalgesia in your right hand and right leg.

If this heightened sensitivity continues it may develop into widespread pain. This is thought to be one of the mechanisms in fibromyalgia. It is also extremely common in neck pain and back pain. Most patients who have experienced a whiplash or disc herniation experience primary and secondary hyperalgesia.

Patients with chronic low back pain with pain that travels into their legs often say to me “if you could just massage my painful leg I think my back pain would go”, in reality it’s actually the other way around. It’s a conversation chiropractors have everyday.

Can chronic pain improve?

The good news is that if the primary source of pain is removed, then pain can return to normal incredibly quickly. One study found that only 60 minutes after a nerve block, patients suffering from chronic whiplash associated disorder showed significant improvements in both primary and secondary hyperalgesia. Meaning that not only did their neck pain improve, but they could tolerate pain much better in the arms and legs.

The key is to find the source.

Chiropractors don’t use injections or medication. Instead we use a combination of therapies aimed at improving mobility and the control of movement, balance, posture and pain. These techniques help the nervous system to reset, reducing pain and improving movement.

At our chiropractic clinic in Woking we’re focused on chronic pain. With most patients consulting us for chronic back pain, neck pain, shoulder pain or headaches. Whatever the cause, the story of pain sensitisation is usually the same. An initial injury, followed by pain that progressively increased in intensity, frequency and started to spread. I’m pleased to say that we are very effective in stopping and reversing that story.


Staud, R., Weyl, E. E., Price, D. D., & Robinson, M. E. (2012). Mechanical and heat hyperalgesia highly predict clinical pain intensity in patients with chronic musculoskeletal pain syndromes. The journal of pain : official journal of the American Pain Society, 13(8), 725–735. doi:10.1016/j.jpain.

Schneider GM, Smith AD, Hooper A, Stratford P, Schneider KJ, Westaway MD, Frizzell B, Olson L. Minimizing the source of nociception and its concurrent effect on sensory hypersensitivity: an exploratory study in chronic whiplash patients. BMC Musculoskelet Disord. 2010 Feb 9;11:29. doi: 10.1186/1471-2474-11-29.

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