system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is a mouth ulcer?

What exactly is a mouth ulcer? What's in it, what is it made of? Why does saline and mouthwash help, and why does acid encourage it? Also, can I cut it out of my lip?

EDIT: When I say cut, I mean, it's sticking out more that the rest of my mouth gummy skin, so like, how'd you'd peel a scab, but with the ulcer.
gpt
No you cannot cut it out of your lip, put down those scissors! It is more like a blister than a cyst; you need the skin etc., don't cut it out!

I'll let someone more knowledgable answer the rest of your question. But just wanted to make sure someone said this before you got impatient and picked up a bread knife.