"This Won't Hurt a Bit." Oh Yes, It Will

We've all been there.  The nurse coming toward us with the needle, or, as in my recent ase, the resident saying "This won't hurt" as he yanks the broken bone in your wrist to try to put it back in place.

Why do these people say this, and why does it hurt so much more when they say it?

A new study has found that when this happens -- your expectations violated, and not in a good way -- it's because our expectations of pain affect the experience of pain, according to Fadel Zeidan, Ph.D., assistant professor of neurobiology and anatomy at Wake Forest Baptist and first author of the study, at newswise.com. “This effect shows us how important it is to manage people’s expectations when it comes to pain," he says.

Duh.  

Previous studies have shown that the expectation of intense pain can make pain feel worse while the expectation of milder pain can actually make it hurt less. It all has something to do with areas of the brain but all I know is, I don't want to feel pain and when I'm around healthcare professionals, I often do.

Subjects in the study were trained to expect mild or intense levels of pain when showed visual cues of the words “low” and “high.” Different levels of heat were applied to the participants’ legs with thermal probes, some high and some low. 

Then the participants underwent functional neuro-imaging scanning to measure their brain activity while they received the different levels of heat following both correct and incorrect cues.  Individuals felt intense pain when the cue was "high" and the unpleasantness was indeed very strong.  But when they saw "low," the pain went down, even if it actually was intensified.

And guess what?  Participants felt much more pain when they were given the "high" cue, than when they were given the "low," even when the pain was fierce.


These findings demonstrate that the powerful influence of expectations on the subjective experience of pain can be dramatically altered when there is a substantial difference between expected and experienced pain, Zeidan says.

“Knowing how vital trust is to the doctor-patient relationship, we hope these findings will help physicians and other caregivers have a better understanding of the importance of how what patients expect affects their experience of pain,” he adds.

So are you not going to brace when the nurse brandishes the needle?  Probably not.  But maybe just think in your head of a cool, clear lake where the breeze is mild -- aw, never mind.