In the previous post, we looked at the ways our models of pain have changed over the years, which has contributed to a shift in how we view pain, healing and the body as a whole. This week, we'll be looking at the relationship between pain and tissue damage, or injury. Does pain always mean there is injury to the body? Do we always feel pain where there is measurable damage?
It frequently happens that tissue damage and pain occur commensurate with one another. So it’s understandable that many of us perceive that a great deal of pain must signify a great deal of damage in the body. Or conversely, that no pain means there’s no problem. We know now that the relationship between pain and tissue damage isn’t nearly so straightforward as our intuition might suggest. We know now that it is possible to have significant damage with no pain at all, and that a previously unimaginable number of people do.
In one study of people with no reported shoulder pain, 23% overall were found to have rotator cuff tears, and in one of these study groups 51% showed signs of tear and yet had no pain at all. Zero. Zilch. Do you find that surprising?
In studies of the knees, the numbers are even more striking. When researchers studied the knees of asymptomatic volunteers between the ages of 20 and 68, they found that all but one of them had some damage to the meniscus, and that fully 61% showed signs of damage in at least three of the four regions of the knee.
When researchers studied the lumbar spines of people with no back pain, they found that
52% of their subjects had at least one disc bulge, and that 38% had abnormalities in more than one disc.
A great deal of damage can be present without making us wince, it seems.
To the relief and validation of a great many people, we’ve also come to understand that people can and do experience pain – real pain – without the presence of any tissue damage at all. We know that amputees experience phantom limb pain in great numbers, especially if they experienced pain in the limb prior to amputation. And we know that this pain is as intense and as real as any limb pain you or I might experience in our palpable, visible and fully intact limbs.
Pain can also show up as an abnormal response to previously innocuous triggers. We’ve come to understand that in allodynia, people experience real pain in response to stimuli normally not associated with pain responses. And in hyperalgesia, others experience a far greater pain response than is typical even to a stimulus normally associated with pain responses. We know that these pain episodes are very real for those experiencing them, are legitimately occurring in the brain, and that they are neither exaggerations or fabrications. This invisible pain really hurts!
So we have seen that pain can exist without a corresponding injury, and that substantial damage can exist without pain.
What understandings have these discoveries given us regarding the function or purpose of pain? We'll explore that question in the next blog post. Until then, breathe deeply, practice often, be well.
Dana Wyss Healing Arts