What causes blisters in the mouth?

What causes blisters in the mouth?

Canker Sores No one knows what causes these small, painful blisters inside your mouth. Triggers include hypersensitivity, infection, hormones, stress, and not getting enough of some vitamins. Also called aphthous ulcers, canker sores can show up on the tongue, cheek, even your gums. They usually last a week or two.

How long do canker sores last?

They may be swollen and painful. Having a canker sore can make it hard to talk or eat. Canker sores may hurt for 7 to 10 days. Minor canker sores heal completely in 1 to 3 weeks, but major canker sores can take up to 6 weeks to heal.