What is a mouth ulcer?

Mouth ulcers are painful sores in the oral mucous membrane. They usually have an oval or round shape and a diameter of three to four millimetres. A mouth ulcer is grey, white or yellow in colour with a red inflamed edge. They appear on the inside of the cheek, lips, gums or under the tongue. Mouth ulcers can occur singly or in groups and usually disappear within one or two weeks. There are three types of mouth ulcers, minor ulcer, major ulcer and herpetiform ulcers. Sometimes mouth ulcers are very persistent and keep coming back, this is called recurrent oral ulceration (ROU). Mouth ulcers cause a stinging pain and burning sensation when eating acids or hot spicy food. Mouth ulcers are a very common oral lesion, and many people will suffer at least once in their life. They are particularly common among children under the age of 15. Mouth ulcers are not contagious or damaging to your health. The cause of mouth ulcers is still unclear to this day.

Mouth ulcers are also known as:

Aphthous ulcers
Canker sores
Oral ulcer
Recurrent oral ulceration

Mouth ulcer lifecycle

The mouth ulcer begins as a small round red swelling on the skin. At this stage the ulcer gives a burning and tingling feeling in a certain area of the mouth. The area is red and looks inflamed and sometimes raised.

1-3 days

After a day the mouth ulcer will burst open into a small lesion. The ruptured sore(s) are covered by a thin white or yellow membrane with an red inflamed border. Pain and discomfort when eating, drinking and speaking comes into play.

3-7 days

The mouth ulcer is now full grown, normally a diameter of 3 to 4 millimetres. The ulcer still

causes a lot of pain.

7-14 days

Mouth ulcer slowly recedes and will disappear within 10-14 days. Pain slightly decreases as the mouth ulcer(s) gets smaller. In some situations mouth ulcers can last for several months or keep occurring every two weeks.