Also known as aphthous ulcers, mouth ulcers are painful, clearly defined, round or oval sores that form in the mouth.
There are three main types of mouth ulcer, which are outlined below.
Minor ulcers are the most common type of ulcer. They account for 80% of all mouth ulcers. They are small (2-8mm in diameter) and normally heal naturally within 10-14 days. A minor ulcer will not cause any scarring.
Major ulcers are deeper and larger than minor ulcers, and usually have a raised or irregular border. A major ulcer is usually 1cm or more in diameter. This type of ulcer will heal more slowly, over a period of several weeks, and can cause scarring. Approximately 10% of mouth ulcers are major.
Herpetiform ulcers form as multiple, pinhead-sized sores. The number of ulcers can range from five to 100. These tiny ulcers often fuse together to form larger, irregular shaped sores, which are extremely painful. Approximately 5-10% of mouth ulcers are herpetiform.
A mouth ulcer is a very common condition, and most people will have at least one in their lifetime. Studies have shown that mouth ulcers are more common in women and people who are under 40 years of age.
Mouth ulcers cannot be passed from person to person. For example, you cannot get an ulcer from kissing someone, or from sharing a glass or cutlery.
Recurrent ulcers
Most people will only have a mouth ulcer occasionally. However, for some people, mouth ulcers recur on a frequent basis. In the UK, 20% of people (one person in every five) will experience recurrent mouth ulcers.
Recurrent mouth ulcers are often caused by different factors than single ulcers. See the "causes" section for more information.
