HAVE YOU EVER WONDERED...
Itching (pruritus) is caused by an irritant such as bugs, dust, clothing fibres and hair. It’s a built-in defence mechanism to alert your body to potentially being harmed.
Once hair or dust scratches the surface of your skin’s nerve receptors, the skin becomes irritated. In a split second, these receptors send a signal through nerve fibres to your spinal cord and then up to the cerebral cortex in your brain where they’re actually felt as an itch.
As soon as we feel an itch we scratch the spot with our fingernails. The reason for this is that we want to remove the irritant as soon as possible. Once you’ve scratched the area of irritation you will feel relief.
When your brain realises you’ve scratched away the irritant, the signal being sent to it that you have an itch is interrupted and therefore is no longer felt by the brain.