Mouth ulcers are painful sores that appear in the mouth. Although they’re uncomfortable, they’re usually harmless and most clear up by themselves within a week or two.
Mouth ulcers are common and can usually be managed at home, without seeing your dentist or GP. Visit your pharmacist first, unless your ulcer has lasted longer than three weeks.
What does a mouth ulcer look like?
Mouth ulcers are usually round or oval sores that commonly appear inside the mouth on the:
They can be white, red, yellow or grey in colour and swollen.
It’s possible to have more than one mouth ulcer at a time and they may spread or grow.Mouth ulcers shouldn’t be confused with cold sores, which are small blisters that develop on the lips or around the mouth. Cold sores often begin with a tingling, itching or burning sensation around your mouth.
When to see your pharmacist, dentist or GP
Mouth ulcers can be painful, which can make it uncomfortable to eat, drink or brush your teeth.It’s usually safe to treat mouth ulcers at home. See your GP or dentist if:
your mouth ulcer has lasted three weeks
you keep getting mouth ulcers
your mouth ulcer becomes more painful or red – this could be a sign of a bacterial infection, which may need treatment withantibiotics
How to treat mouth ulcers
Mouth ulcers don’t usually need to be treated, because they tend to clear up by themselves within a week or two.
However, treatment can help to reduce swelling and ease any discomfort. This may help if you keep getting mouth ulcers or your mouth ulcer affects eating and drinking.
What causes mouth ulcers?
In many cases, the reason for mouth ulcers is unclear. Most single mouth ulcers are caused by damage to the lining inside of the mouth. For example:
- accidentally biting the inside of your cheek or a sharp tooth
- poorly fitting dentures
- hard food
- a defective filling
- It’s not always clear what causes mouth ulcers that keep returning, but triggers are thought to include:
- stress and anxiety
- hormonal changes – some women develop mouth ulcers during their monthly period
- eating certain foods – such as chocolate, spicy foods, coffee, peanuts, almonds, strawberries, cheese, tomatoes and wheat flour
- toothpaste containing sodium lauryl sulphate
- stopping smoking – when you first stop smoking, you may develop mouth ulcers
- Your genes are also thought to have a role – around 40% of people who keep getting mouth ulcers report that it runs in their family.