What happens to your body when you experience pain?

Pain is a normal part of the human experience. So normal, in fact, that it’s necessary for our survival.

It’s main function: protection.

Any parent can see this life lesson play out whenever a curious child learns the hard way about touching something sharp or hot. And in those examples, the function of pain seems to be working as designed.

But if the purpose of pain is protection, what about those of us in constant pain? Surely, the idea would seem absurd to the person who cannot escape it.

According to a 2012 survey conducted by the National Institutes of Health, 11 percent of Americans are living with chronic pain. It is clear that something is being lost in our understanding and treatment of it.

Fortunately, new research in pain science provides a better understanding of what is happening when we experience pain. This is what is being called by some in the field as “The Pain Revolution.” Stated simply, pain is not a reflection of damage inflicted on our bodies.

The brain acts like an extremely fast computer processor that takes in not only biological information via our nervous system, but also psychological and sociological information (such as past experience, surroundings, fear, confusion, concern) and makes a decision to create a pain response, or not, based on whether a threat is perceived. The value in this centers around the idea that we can influence the factors being weighed and ultimately change the outcome of the “pain equation” in our brains. It’s a scale weighing danger versus safety. If danger wins, then the alarm bells of pain will go off. If safety wins, we get to move on with our lives.

To help illustrate the concept, consider the following story published in The BMJ in 1995:

A 29-year-old builder is rushed to an ER screaming in pain with a 6-inch nail sticking out of the top of his boot. He had jumped off a platform and landed on the nail. In attempting to remove the nail, the slightest movement sent the man into further searing pain. He was given an opioid and a sedative to calm him down enough to allow the removal of the nail, and then eventually the boot. Upon removing the boot, doctors realize the nail had not injured the man’s foot at all — it had passed cleanly between his toes.

So was the man’s pain real? Absolutely. The visual information the man received from seeing a nail seemingly penetrate straight through his foot was enough (mis)information to convince his brain that action must be taken – sending a distress signal of pain seemed warranted.

The story of the builder provides a good example of how the brain decided to create pain despite there being no bodily damage, but what about the other side of that coin?

Consider the story of Scottish WWII veteran Robert Kincaid who at the age of 84 was informed by his doctors after an X-ray that he had a bullet lodged in his neck. Kincaid was shocked to hear this news, as he had no recollection of being shot — although he certainly remembers being shot at.

But if pain is supposed to protect you, why would no pain be produced to alert Kincaid to his injury? Because of context. In a war zone and under fire, Kincaid needed all of his focus on his surroundings, and his brain made the decision to forego the pain response as crippling pain in those moments certainly would not have been helpful for survival.

The real value in these stories is that they are not exceptions to the rules of how pain operates. Instead, they perfectly highlight a set of rules we are just now beginning to understand. And this improved understanding of pain can provide new treatment approaches with better outcomes for people who have been suffering with chronic pain.

Many chronic pain sufferers have been told by the medical community that there is no great explanation for their experience. Our outdated ideas about pain have failed this population.

Imagine how this lack of understanding can all feed back into the “pain equation” by highlighting fear, hopelessness, doubt, anxiety, anger, resentment, and frustration – emotional responses that reinforce a sense of continued danger. But considering the improved understanding of how pain is created, we can turn the fear of chronic pain patients that their body is broken into trust that their bodies are operating fantastically as self-healers. Instead of fearing that movement will cause harm, we now have understanding that a slow introduction of physical activity can facilitate normal and healthy movement patterns. From the hopelessness and resentment that comes with yet another pain prescription to the confidence that science believes your pain is real and can help you make sense of the madness. From danger to safety. This is where the pain revolution can be fought and won.

Todd O’Leary, PTA, is an outpatient physical therapist at Thomas Jefferson University Hospital.