A mouth ulcer can make eating and talking painful, even though it's tiny. The common round, white or yellow sores with a red border are usually harmless and heal on their own within 7–14 days.
Common causes
- Accidentally biting your cheek or tongue
- A sharp tooth, broken filling or rubbing denture
- Stress and lack of sleep
- Spicy or acidic foods in some people
- Low iron, vitamin B12 or folate
Easing the pain
- Rinse with warm salt water a few times a day
- Avoid very spicy, salty or acidic food until it heals
- Use a soft toothbrush and be gentle around the area
- Ask your dentist or pharmacist about a soothing gel
When to see a dentist
- An ulcer that hasn't healed in two weeks
- A painless patch or lump, especially if you use tobacco
- Ulcers that keep coming back often
- A sharp tooth or denture that keeps causing sores
This article is general information, not a diagnosis. Please visit a dentist for advice about your own teeth.