system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is happening to my nervous system when doctors numb an area of my body?

I recently had my wisdom teeth removed and the dentist numbed the back of my mouth. Then, proceeded to yank two huge wisdom teeth out while blood was spouting everywhere. All the while, even though I was conscious the whole time, I felt nothing. Why?
gpt
You feel pain (as well as touch) via nerves that transmit 'information' from your mouth and around your teeth to your brain. The information your brain receives is interpreted, where you consciously sense it.
Anaesthesia is a medication that acts to block the nerve, thereby not allowing it to transmit any information. This is usually injected to the area needed so it will only block the close nerves where it would have a local effect only (i.e. it won't travel far into your body to have any effect on the remaining nerves).
No nerve conducting information to brain means no sensation of pain or touch in that region. When the drug's effect wear off, nerves conduct again and you feel normally again.