I’ve been plagued with canker sores since I was approximately 7 years old, and I’ve cursed every single one of them. They make eating painful and embarrassing—chomping down on one can make you see stars, forcing you to chew gingerly with your mouth half open—and I sometimes get awful Cheerio-sized sores that ache so much they wake me up at night. Luckily they’re not contagious, but that’s really the only positive thing about them.
Not to be confused with cold sores, canker sores are open wounds that form in the soft tissue inside the mouth, usually on the inner lips and cheeks, gums, and tongue. (Cold sores, on the other hand, are blisters on the lips and outer edges of the mouth caused by the herpes simplex virus.) The ulcers are typically white and round, with an angry red ring around the outer edge.