Why the Act of Scratching an Itch Is Really Just a Trick to Fool the Brain Into Feeling a Sense of Relief

Why do we itch

In a fascinating Ted Ed lesson based upon the work of educator Emma Bryce and animated by Sashko Danylenko, a narrator explains the physiological reasons behind skin itches, what causes itching and how the act of scratching an itch is really a distracting misdirections that tricks the brain into feeling a sense of relief.

Researchers have discovered that itch signals in their skin are transmitted via a subclass of the nerves that are associated with pain. These dedicated nerves produce a molecule called natriuretic polypetide B, which triggers a signal that’s carried up the spinal cord to the brain, where it creates the feeling of an itch. When we scratch, the action of our fingernails on the skin causes a low level pain signal that overrides the itching sensation. It’s almost like a distraction, which creates the sensation of relief.

Lori Dorn
Lori Dorn

Lori is a Laughing Squid Contributing Editor based in New York City who has been writing blog posts for over a decade. She also enjoys making jewelry, playing guitar, taking photos and mixing craft cocktails.