Question: what is it called when you have a sore in your mouth?
Answer: Canker sores can have several causes or triggers. Canker sores, also called aphthous ulcers, are small, painful sores that appear inside the mouth on the lips, cheeks, on the gums, and tongue. They are appropriately named, too: In Greek, aphthae (root of aphthous) means "to set on fire."