By Jake Foster, PA

Our understanding of pain has evolved quite a bit during recent years. When I first learned about pain in a high school biology class, it seemed pretty straightforward: a pain receptor detects tissue damage, a series of nerves transmit that signal to your brain, and you are made aware of the damage. Having this system in place then allows us to react when we have some sort of insult to our tissues, and we are able to prevent further tissue damage and injury. It’s a nice way to explain pain, but it turns out that the reality of the pain we feel in our bodies is much more complicated than that.

Consider an experiment published in the publication Nature in 1998. In the experiment, subjects were made to believe that a rubber hand was actually their real hand. This was done by blocking the person’s real right hand from their view, while at the same time placing a rubber hand in a position where it appeared to be their left hand. The experimenters would then stroke both the rubber hand (in view) and the real hand (not in view) synchronously. After this was done for about 10 minutes, the subjects’ brains were tricked into thinking that the rubber hand was their actual left hand. Several interesting tests followed, including one where the experimenters were actually able to elicit a sensation of pain in the subjects by poking the rubber hand.

This illustrates that pain is far more than a pain receptor detecting an injury and communicating that accurately with our brain. It implies that a large part of our pain is actually interpreted by our brain. In other words, pain is a subjective experience in which our pain plays a major role in interpreting the kind of pain we experience. This is especially true for certain types of chronic, or long term pain. We have learned that the pain we experience in our bodies does not always correspond to an injury in our body, like feeling pain when a fake rubber hand is poked.

Pain is how our body protects itself. When we have a sensation of pain, our brain interprets that sensation as an unpleasant feeling that corresponds to the level of injury we have in our tissues. The problem with this idea is that many people experience pain that does not correspond to an injury. It is very common, for example, to have severe low back pain for which no obvious cause of pain can be detected by an expensive MRI. The opposite is also true: an MRI can show injuries or degeneration in the lumbar spine which does not cause any perceptible pain in a person.

Now, this is not saying that just because an injury cannot be detected, does not mean that the person is actually not in pain. As medical providers, we absolutely believe you when you tell us you are experiencing pain. Pain is very real, regardless of whether it corresponds to an obvious injury or not.

Our new and evolving understanding of pain has led to new and evolving ways to treat pain. Because chronic pain is very often a complex problem, it stands to reason that it might very well require a complex solution to address it. Often, chronic pain is best treated by having a multidisciplinary approach. This may include certain types of medicines that can reduce inflammation, or help to slow pain signals in your body, or even to help how your brain might receive and interpret pain signals. But medicine is proving to be only a single part of a good plan for treating chronic pain. We are increasingly seeing that therapy can also help to alter the course of pain in peoples’ lives; both physical therapy as well as psychological therapy.