Look Away from the Needle

Pain perception may be a key factor in how people experience greater intensity of pain

(RxWiki News) Does looking at the needle when you’re getting a shot or giving blood make it hurt more? There may be actual science behind the old saying, “Don’t look and it won’t hurt”.

Researchers looked at how people perceive pain vs. how they actually feel pain. Findings support the idea that what clinicians say before they prick a patient can affect how intense the pain actually feels.

"Don’t look at the needle!"

Marion Höfle, doctoral student in research at the Multisensory Integration group run by Dr. Daniel Senkowski PhD, at the Charité – Universitätsmedizin Berlin and the University Medical Center Hamburg-Eppendorf, was the lead author of this study on pain and perception.

Previous experience with sharp objects and pain, as well as the information given to a patient by the medical personnel right before they are poked with a sharp object can influence the severity of pain felt by the patient. There are certain aspects to this kind of pain that are learned through experience.

“Throughout our lives, we repeatedly experience that needles cause pain when pricking our skin, but situational expectations, like information given by the clinician prior to an injection, may also influence how viewing needle pricks affects pain.”

For the study, researchers set up the participants with a video that showed a hand on a screen right above their own hand so that patients were meant to see the video hand as their own hand. The video hand was either pricked with a needle or poked with a Q-tip. While they were watching the video clips the participants were also being given either painful or non-painful electrical stimuli to their hands.

Researchers monitored pupil dilation, intensity and unpleasantness ratings. Pupil dilation is a response of the autonomic nervous system, which is an involuntary reaction to many things, including fear.

Pupil dilation and unpleasantness ratings were higher with the electrical stimuli on the participant’s hand when the participants were being shown the video clips where the hand was being pricked with a needle vs. poked with a Q-tip.

Intensity ratings were higher when the researchers talked about the expectation of painful vs. non-painful stimuli before administering it to the hand.

This suggests that being nervous or afraid of the pain makes it worse.

Höfle states, “Clinicians may be advised to provide information that reduces a patient’s expectation about the strength of forthcoming pain prior to an injection. Because viewing a needle prick leads to enhanced pain perception as well as to enhanced autonomic nervous system activity, we’ve provided empirical evidence in favor of the common advice not to look at the needle prick when receiving an injection."

This study was published in the journal Pain, May 2012. No financial information was given and no conflicts of interest were reported.

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Review Date: 
May 21, 2012