Mouth ulcers Dr Rob Hicks Most people suffer with a mouth ulcer every now and then. They're extremely common and usually painful, appearing as little craters in the lining of the mouth.

In this article

What are they?

What causes them?

Can I prevent them?

A mouth ulcer is an exposed nerve. The lining of your mouth is incredibly sensitive and any break in its surface exposes the nerves that lie in and beneath it. Anything that touches them, whether it's food, liquid or a toothbrush, causes pain that means it can be difficult to eat, drink and even talk.

Accidental damage is responsible for many - brushing your teeth too hard, minor burns from hot food and drinks, biting the inside of the mouth accidentally, a tooth that's become rough, or orthodontic braces that rub against the gums.

These last for a week or more unless the damage continues happening, in which case they will not disappear until the cause - for example, a rough tooth - is treated.

The other common type is an aphthous ulcer, which occurs when someone's feeling stressed or under the weather. They often appear for the first time during puberty and they can run in families.

These can take a couple of weeks to heal and are likely to keep appearing until someone's feeling relaxed and well again.

Other more serious causes of mouth ulcers include herpes infection, inflammatory bowel disease and immune disorders, but these are usually accompanied by other symptoms around the body.

Sometimes a deficiency in iron, vitamin B12 or folate is the underlying cause, which is why anyone who keeps getting ulcers or who has ulcers that are not healing should consult their doctor.

Practise good dental hygiene, taking care not to damage your teeth and gums, and visit the dentist as often as advised.

Eating a healthy, varied diet, which includes fruits, vegetables, wholegrains, milk, fish and lean red meat, will supply your body with the necessary vitamins, zinc and iron to maintain a strong immune system that can resist infections.

Avoiding food and drinks that are too hot is sensible, and try to relax and keep stress under control.

What's the treatment?

Gargling and swallowing soluble paracetamol relieves the pain, and rinsing the mouth with iced water before a meal makes eating possible.

Pastilles and gels that contain anaesthetic have been the mainstay of treatment for years.

Those looking for a more natural treatment use camomile tea. Allow it to cool, then swill it around the mouth before swallowing it.

Other popular remedies include echinacea, myrrh, licorice with the glycyrrhizic acid removed (called deglycyrrhizinated licorice or DGL) and products containing hyaluronan.

This article was last medically reviewed by Dr Rob Hicks in May 2008