The neuroscience of how the brain ‘switches off’ pain

In the second world war, the physician Henry Beecher observed that some of his soldier patients, despite being injured on the battlefield, required no strong painkillers to manage their pain. In some cases, the injury was as severe as losing part of a limb.

A truly remarkable phenomenon had come into play – the effects of fear, stress and emotion on the brain had switched off their pain. But how does this work – and how can we use it to our advantage?

We all struggle with pain at times. The burning of indigestion, the wince of a scald from the kettle. The sharp stabbing of a sliced finger.

But despite its unpleasantness, pain has a critically important purpose, designed to protect the body rather than harm it. A fundamental concept to first understand is that you do not detect pain – it is a sensation. A sensation that your brain has created – from information it receives from the countless neurons (nerve cells) which supply your skin.

These specialised neurons are called nociceptors – they detect stimuli which are noxious, or potentially damaging to the body. This stimulation might range from a mechanical cut or crush injury, to extreme hot or cold temperatures.

So, if you touch a hot iron, or stand on...

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