Smile Mouth ulcers: when to see a dentist or doctor
Most mouth ulcers go away on their own in about 10 to 14 days. See a dentist or doctor if a mouth ulcer lasts longer than 3 weeks.
What to expect
In most cases mouth ulcers are harmless and heal in about 10 to 14 days.
See a dentist or doctor if
- an ulcer has not healed after 3 weeks
- you have a red or white patch inside your mouth
- you have a lump inside your mouth or on your lip
- you have pain in your mouth, trouble swallowing or speaking, or a hoarse voice
- new sores appear before old ones heal, or sores are unusually large or painless
A long-lasting mouth ulcer is sometimes a sign of mouth cancer, which is why it is worth getting checked. Early checks matter.
Photo notes with Smile Scan
Use Check lips or tongue in the app to add 1 to 3 photos of a sore or spot. It looks for mouth sores and ulcers, swelling, lumps, patches of a different colour, cracks and dryness, and tells you when to see a dentist or doctor. The app suggests getting a sore checked if it lasts about two weeks, which is earlier than the 3-week NHS guidance above, so when in doubt get it checked sooner. It does not assess cancer or serious disease and does not replace a professional exam.
Quick answers
How long does a mouth ulcer last?
Most heal in about 10 to 14 days.
When is a mouth ulcer serious?
If it lasts longer than 3 weeks, or comes with a lump, red or white patch, or trouble swallowing, see a dentist or doctor.
Take 5 guided photos with Yuktii Smile Scan, ask the AI teeth assistant, and find a dentist near you, worldwide.
Get the app