The pain centres deep in the brain are like a movie projector. They project pain onto a body part that needs to be protected or tended to. Physical harm happens in the body, but the pain that alerts us to harm happens deep in the brain.

Pain happens in the brain, but of course, the body is also involved in the process; of course it is. 

In order for pain to happen in the brain, there needs to be some raw data input from the body, which gets translated into ‘felt pain’. Scientists call this raw data ‘nociception’. Nociception is the raw data the body generates when it senses harm. Raw data that gives rise to the pain we feel, but only when the brain decides it’s necessary. If the brain doesn’t ‘tune in’ to nociception, there is no pain at all. But, generally, it is a pretty reliable process.

If you touch a hot stove, nociceptor signals fire in your finger and sends raw data to the brain. The brain reads the incoming raw data and translates it into finger pain to advise you of your mistake.

There are, however, times when things can get a little more squirrely, and it is these moments that give the game away.

Have you ever cut or burned your finger and felt the pain an inch or more away from the injury? Or even in the wrong finger? Perhaps you haven’t personally, but many of us have. This is the brain slightly misinterpreting the raw nociception that came up the spinal cord. 

Other more extreme examples include people who are shot or stabbed and feel no pain at all until they discover a hole. In these instances, the brain completely fails to process the incoming raw data, leading temporarily, at least, to severe injury with no pain whatsoever. 

There are many other well-known anomalies that highlight the true ‘brain-based’ nature of pain. Phantom limb pain, for example. Completely sane patients with headaches outside their heads. Painless surgery under hypnosis. Painless religious ceremonies that involve kebab skewers. And many more examples besides.

The raw nociception data generated by the body when it’s harmed is a bit like a radio wave. Radio waves are utterly ‘silent’ until the radio apparatus translates the signal. The brain is like the radio; it translates the incoming signal, and that’s when the pain experience arises.

Understanding this aspect of pain is a gateway to understanding the possible causes of your chronic pain. For example, the fact that pain happens deep in the brain highlights how it is that chronic pain is so much more common in sufferers of conditions like PTSD and anxiety disorders.