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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.
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.
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:
Mouth ulcers are also a possible symptom of a viral infection that mainly affects young children, called hand, foot and mouth disease. Speak to your GP or call NHS 111 if you're unsure.
Read about the symptoms of hand, foot and mouth disease.
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.
Things you can do to speed up healing include:
You can buy several types of mouth ulcer treatment from a pharmacy. Speak to your pharmacist about the best treatment for you. Options include the following:
If necessary, you may be prescribed a course of stronger corticosteroids to help reduce pain and swelling, and speed up healing.
Corticosteroids are available on prescription as tablets, mouthwash, paste or spray, but are not suitable for children under 12.
In a few cases, a long-lasting mouth ulcer can be a sign of mouth cancer. Ulcers caused by mouth cancer usually appear on or under the tongue, although you can get them in other areas of the mouth.
Risk factors for mouth cancer include:
It's important to detect mouth cancer as early as possible. If mouth cancer is detected early, the chances of a complete recovery are good. Regular dental check-ups are the best way to detect the early signs.
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:
It’s not always clear what causes mouth ulcers that keep returning, but triggers are thought to include:
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.
Mouth ulcers can sometimes be caused by certain medical conditions, such as:
Mouth ulcers can sometimes be caused by certain medications or treatments, such as:
It may not be possible to prevent mouth ulcers, because they're often caused by things you can't control (such as a family history or a medical condition).
However, the following may help to reduce your risk of developing mouth ulcers:
Read more advice on dental health.