system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do things itch and why does scratching help?
gpt
Itching occurs when more skin cells die in a particular area of skin than the skin can naturally slough at one time, sending a nervous signal to the brain to eliminate them, and scratching the itch removes("sloughs") the dead skin cells...depositing them underneath your fingernails.