Pain is a survival mechanism. It exists as a threat detection system motivating us to do something. What happens when you put your hand on a hot stove? You pull that hand back, protect the painful body part and move out of harm’s way. Or what about acute appendicitis? Man, that is painful and for good reason. That situation is serious. If not taken care of death can ensue.
Without the ability to feel pain we would be unable to detect what is harmful to us. How long do you think we’d last? Although extremely rare, there have been people born with the inability to feel pain. Sounds ideal right? Well it isn’t. This is actually a horrible disease that leads to a reduced life expectancy and it shows us just how essential pain is to our survival. As babies, the afflicted chew their fingers and tongues severely. They have no fear of fire, stoves, knives, or falling down. All these things lead to serious injury. As adults they tend to sustain multiple orthopedic injuries that won’t heal properly because insensitivity to pain prevents people from restricting their activities. This is hardly ideal.
All this demonstrates just how essential pain is to our development. It is also a key component in our ability to survive. So, you could say that pain is an advantage in the grand scheme of things and to live without it would be a massive handicap.
What about the other side of the coin? There are many people living with never ending pain. Maybe they haven’t even sustained any trauma. Sometimes pain is a part of our lives with no reasonable explanation.
There is a huge financial burden that comes with chronic pain. In Canada, that cost was $56-60 billion in 2014 in health care costs and lost productivity, (click here for reference). In the U.S. that burden has been estimated at about $635 billion dollars a year. To put that in perspective, the war on terror since the year 2000 has cost a total of 1.7 trillion dollars. Just imagine how many more wars could be waged if we could save on the pain expenditures.
Economical cost aside, there has been a massive paradigm shift in how we view pain. For over 300 years we have viewed it as a bottom up phenomenon. That is, we thought that pain was a direct result of tissue damage and that the amount of damage correlated directly to the amount of pain one would feel. When we think of that now, we see that it is obviously faulty reasoning. It doesn’t explain why people feel pain long after tissues have healed, (generally 3-6 months). It doesn’t explain why we see chronic pain conditions such as fibromyalgia wherein a patient presents with no tissue damage. We had to be missing something.
We know now that pain is a top down phenomenon, that pain is an experience produced by the brain. It is an output from the brain, rather than an input from the body. When we sustain tissue damage, sensory nerve endings send signals from the damaged tissues to the brain: we call this nociception. In layman’s terms this means danger signals. This is the body’s way of signaling to the brain that there is a potential threat. No pain is felt until the brain interprets these signals and makes a decision whether or not it’s in our best interest (to our survival) to feel pain. Nociception is just one of the multiple factors involved in the pain experience that the brain considers before any pain is felt. These may include sensory cues, past experience, beliefs, emotions, social context, future intentions and virtually anything that the brain decides is important to ensuring our survival. In other words, pain is powerfully influenced by perception and more specifically our perception of how safe we are.
Episodes of pain can be triggered by a multitude of factors, many of which are unrelated to physical damage. It has been shown that depression, anxiety, stress, and inadequate sleep can all contribute to higher levels of pain. Recent research suggests if we experience pain for long enough our brains can learn to associate emotions, thoughts or movements with pain, (click here for reference).
This means that even thinking a thought or moving a certain way can elicit a pain response. Nerves that fire together, wire together. The most famous example of this is Pavlov’s dogs. The bell would ring then the food would be served. This happened enough that the dogs had learned to associate hearing the bell with receiving food. The dogs had been conditioned to salivate in anticipation of being fed when the bell was rung. It’s possible that the brain can be conditioned to produce pain in the same manner. For example, every time you go to your stressful job you experience back pain from sitting at a desk all day or moving heavy objects. After a prolonged period your brain will associate your work environment with the pain and you may only need to show up or even think about work to feel pain. Seems a little unfair doesn’t it.
In general this is a complex subject and one that is greatly misunderstood. Pain education is often the first step in learning how to better manage living with pain. I look forward to sharing more insights on this topic in future posts.