If you were bruised or cut and somebody told you your pain was all in your head, you might well feel indignant. Even if your pain was from a headache or strained muscle that no one else could see, you would probably be certain your pain was not a figment of your imagination.
But what if your pain really does exist in your head? Consider this. When you get “freezing” ( an injection of local anesthetic) for dental work, you feel no pain because nerve signals can’t travel along the “frozen” nerve to the brain. Nerve signals have to be decoded and processed ( an analogy with computer processing is unavoidable) in just the right way for you to feel the pain. They don’t simply stimulate the appropriate brain cells for you to feel something.
Furthermore, there are well documented cases of soldiers who have been shot in battle who don’t feel any pain until after getting an injured buddy back to safety. People have undergone abdominal surgery using only hypnosis for anesthesia. In these examples, normal processing of pain signals has somehow been disrupted in ways that medical science cannot yet fully explain.
However, what medical research has shown is fascinating. We now know that what the brain does is far more complex and creative than we imagined. It decodes nerve signals and then actually constructs what we see, hear and feel using not just the information from the incoming nerve signals but other information too. This other information may be related to memory, emotion, learning or any of the other processes the brain is concerned with. One of those processes is consciousness itself. Think of the brain as an incredibly complex computer, processing enormous amounts of data to produce not just the picture on the screen but all the sounds, smells, tastes and sensations we experience in our lives.
Therefore it is easy to think of pain as a sensation that comes into awareness after being literally manufactured by the brain. It is not simply the result of a nerve signal acting like electricity through a wire to turn on the lights. So… yes, whether you stub your toe or have a back ache, it turns out that pain really is “all in your head”. It is the product of complex neurological processes we are only beginning to understand.