What is Pain?

To effectively manage physical pain, whether it be from a small scrape on our knee, to serious injuries suffered in an motor vehicle accident (MVA), we first must understand what pain is and how it works. Unfortunately, pain is a very complex entity that cannot be explained in a single blog entry. Pain can vary in type, intensity, and duration and each one of us interprets pain differently. The International Association for the Study of Pain defines pain as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.” We have all been subjected to pain at one time or another, but why exactly do we “feel” pain and what purpose does it serve?

There are two main, and important, roles that pain plays in human beings:

The first role pain plays, is that it alerts us of damage (or potential damage) to the body. Let’s say while cooking dinner last night, you accidentally place your hand on the hot stove. You feel an immediate burning sensation and severe pain. This onset of this pain is the body’s way of alerting us that damage (ie. burning to your hand) is occurring in that moment.

The second role pain plays is that it protects us from further damage. The onset of pain forces us to change our behaviours/environments in able to avoid additional harm from the painful stimuli. In the stove top example, we feel the pain’s onset and quickly remove our hand from the burner, thus, preventing further damage to the hand. In essence, pain is a survival mechanism. It alerts us when there is danger to the body and forces accompanying change to prevent this danger from becoming serious in nature.

Now, back to the question of why we “feel” pain. First off, pain is typically triggered in the body by “messages” that are sent out from damaged tissues. These “danger” messages are sent by the nerves to special pain receptors in the body called Nociceptors. These messages continue through the nerves, into the spinal cord, and are sent to the brain for interpretation. How the brain interprets the pain signal is a complex case in itself, which we will discuss a bit more in future blog entries.

All of this activity happens within a fraction of a second, and the brain’s interpretation of the pain determines our next actions. Some signals are sent to the motor cortex, motivating us to move away form the painful stimuli. Other signals are sent to limbic system, which determines our emotions related to the pain. In the end, the brain prepares the body to deal with the pain threat. We move away from the painful stimuli and move on to trying to manage this acute event. Eventually, the pain subsides, the wound heals, and we are back to normal.

But what if the pain doesn’t stop? What if we are experiencing pain long after our injuries have healed? This is what is called chronic pain. And now that you know the basics on how pain works, we will be able to further explore the complexities of persistent pain and chronic pain management in future blogs.