Chronic pain remains something of a mystery to researchers, as pain often persists even in the absence of tissue damage.

The answer may lie in the brain’s neuroplasticity, meaning its ability to re-wire in response to new experiences.

If you slam your finger in a door, pain receptors communicate a danger signal to your brain via neural pathways in your nervous system. In response, the brain goes into a state of hyperawareness to address the threat.

If the pain messages continue for an extended time, the neural pathways will re-organise to allow the brain to remain in this hyperaware state for longer.

This process is designed to help the body adapt to injury or incapacity.

Dr Philip Siddall in the Medical Journal of Australia uses the example of a person who has gone blind. Their neural pathways organize themselves so that, when they pick up an object, both their touch and visual cortexes are engaged and they can “see” what they are holding.

When it comes to chronic pain, neuroplasticity becomes problematic. Prolonged pain causes the neural pathways to sensitise, so that they continue detecting a threat even where no threat exists. As a result, even non-threatening stimulation, like a light touch, can result in a pain message being sent to the brain.

According to Dr Petersen-Felix, a Swiss pain researcher, this type of hypersensitivity has been observed in a wide range of conditions, including whiplash, fibromyalgia, osteoarthritis and tension headaches.

In addition, anyone who has ever felt “butterflies in their stomach” before a job interview knows that their mental state is intimately linked with their bodily condition.

Pain is no different. When we feel pain, we process it with multiple areas of our mind, including those to do with emotions and mood.

Emotional distress activates a flight or fight instinct that puts the brain on high alert. When this distress is prolonged, the brain effectively re-wires to maintain hyper sensitivity, increasing pain sensations.

The pain may be “a sensory illusion” but to the patient the suffering is all too real, said Dr Alban Latremoliere of the Harvard Medical School.

When assisting a person suffering from chronic pain, return to work professionals should consider some of the following options:

• Mind-body therapies: these help to improve a person’s mental state, so that the brain’s pathways de-sensitise. Mind-body therapies can include yoga, relaxation techniques, guided imagery and psychological treatment.
   
• Self-management strategies: these help the person feel more in control, which can lower distress and switch off the brain’s “panic mode”. Moreover, many of these strategies activate pleasure receptors to replace constant pain messages. These strategies include a good exercise regime, good sleeping patterns, healthy relationships with loved ones and an improved diet.
   
• Opiates: while these are the most common treatment for chronic pain, opioids can cause listlessness, which can lead to depression. This, in turn, can act to increase pain sensations.
   
• Non-opioid pharmaceuticals: painkillers may assist in controlling pain to allow a person to improve their emotional state. Many other pharmaceutical options are still in the testing stage. Some studies on animals suggest that NMDA-receptor antagonists, such as ketamine, may assist in lowering hyperexcitability of the nervous system. However, the psychometric effects of these drugs make them unsuitable for human tests at this stage.
   
• Return to work process: a return to work process that is stressful has the potential to exacerbate the client’s chronic pain issues. Organisations should seek to manage staff early and well in the aftermath of an injury, with a clearly defined process and reasonable expectations.

Pain receptors act as a complex warning system. An approach that helps the brain dial down the threat level may provide relief for sufferers of chronic pain.