Overview
Mouth ulcers are small, painful sores that form inside the mouth, on the tongue, cheeks or lips. They are very common and usually harmless, caused by minor injury, stress, certain foods or a run-down state. Most heal on their own within a week or two, and simple gels ease the pain. Ulcers that are large, very painful, keep coming back, or last more than three weeks should be checked to rule out other causes.
Symptoms
- One or more round, painful sores inside the mouth
- A white, yellow or grey centre with a red border
- Pain that worsens with spicy, salty or acidic food
- Soreness that makes eating and talking uncomfortable
- Sores that usually heal within one to two weeks
When to see a doctor
See a doctor or dentist for an ulcer that lasts more than three weeks, is unusually large or painful, or keeps recurring.
Emergency — call 108 or go to the nearest hospital
- A mouth ulcer that does not heal within three weeks, especially in someone who smokes or chews tobacco — get it checked to rule out mouth cancer
Causes
Minor injury from biting or hard brushing, stress, hormonal changes, certain foods, and deficiencies of iron or vitamins.