What is Pain?

“an unpleasant sensory or emotional experience associated with actual or potential tissue damage, or described in terms of such damage”  World Health Organization definition.

Even though almost every human being who has ever lived has felt pain, we are still far from being able to explain exactly what goes on when tissue is damaged, how pain becomes chronic and what goes on in the brain and nerves when someone feels pain.

Furthermore, pain is a subjective experience. When you’re hurting, you are the only one who feels it. It’s pretty difficult to study something that you can’t see on a MRI scan or measure with a blood test. Nevertheless, our understanding of pain has increased greatly in the past few decades since the World Health Organization first published its definition acknowledging the subjective nature of pain.

Where is Your Pain?

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 anaesthetic) 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 anaesthesia. 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.

This means that pain as a sensation that comes into awareness after being literally manufactured by the brain. It is not simply the result of nerve signals acting like electricity through a wire to turn on the lights.

So… yes, whether you stub your toe or have a backache, it turns out that pain really is “all in your head”. It is the product of complex processes we are only beginning to understand.

Real and Imaginary Pain

Many people believe that pain is either real or imaginary. They might say that real pain should be treated medically while imaginary pain should be left to the psychiatrists.

But how can we tell real from imaginary pain? Pain is a sensation, not something that can be seen on a MRI or detected with a blood test. Nevertheless, when medical testing fails to find a plausible cause for someone’s pain, many doctors will invoke psychological causes.

This kind of reasoning assumes that our current medical technology is capable of detecting any and all possible organic causes of pain, a dubious assumption at best.  It has only been in the past few years that our technology has allowed us to demonstrate conclusively that conditions such as migraine and fibromyalgia have an organic basis. Chest pain following mastectomy was considered a psychiatric illness for years until it was shown that things like nerve injury during surgery could lead to chronic pain.

As our understanding of how the nervous system works increases, our ability to explain (and treat, we hope) many painful conditions should also increase. It is quite likely therefore that pain now considered imaginary or psychological, only because we have no other explanation, will be found to have an organic basis.

What Pain Is

No matter how you define it, pain is an experience. It is something you feel, regardless of its source. If you feel it, then your pain is as real as anything you see, hear or taste.  This way of looking at it validates the pain of many individuals who may have been told there was nothing wrong or that their pain was all in their heads. In my opinion, the logical responses to such statements include the following. “If nothing is wrong, why do I feel pain?” and “So what if it is all in my head – I still feel it.”

A definition I like is that pain is an unpleasant phenomenon of human experience that has sensory, cognitive and emotional dimensions. Although science has shown us that pain involves complex biological processes that can be triggered by trauma and/or disease, and/or other factors we don’t fully understand, when we feel it, pain seems to permeate our entire being. If there was ever a patient who needed treatment for the whole person, it is the one with chronic pain.


  1. […] is a section from our longer article on “What is Pain”. The reality of chronic pain is a major issue many people confront. Is my pain real or “all […]