system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What happens under our skin when we feel "itchy" and why does scratching it relieve this feeling?
gpt
We have nerve endings in our skin, that send signals to our brain, like “something is pushing me” (touch) or “something is cold” (heat, obviously).

But nerves need to be aroused up to some minimum point to send proper signals.

When they are aroused less then minimum, the brain is confused, and needs to decide; so, it sends down an arm and some fingers to scratch it, so it can decide “is there something wrong” like chemicals or venom or stuff, or is it just that nerve endings need to be rebooted to continue to work normally.