eli5: Why do we feel itchy?


What is the mechanism behind itchiness? Why and how does it happen?

In: Biology


Itchiness is a milder form of pain that indicates something is wrong in the locality of the itch.

Through various chemical cocktails fed to our brain, instead of feeling a flinch response, we feel an urge to scratch.

That is also usually due to the (probably) evolutionary aspect of itchiness. An itch occurs when you’ve got some kind of foreign thing on your body.

Sometimes it feels like the problem is *under* the skin, which in itself is your body probably having evolved to deal with parasites, ingrown hairs, splinters.

The satisfying pain you feel from scratching the itch is your body telling you “good job we dealt with the problem!”