Why do I keep getting mouth ulcers?

Hiraman/Getty If you’ve ever had a mouth ulcer, you’ll know even the smallest sore on your lips, gum, tongue or inside cheek can make eating and talking extremely painful.

Often, these ulcers resolve untreated within one to two weeks .

But recurring mouth ulcers affect up to one in four of us.

Understanding what’s causing them may help you manage and prevent these painful little sores and know when they could be a sign of something more serious.

What are ulcers? Mouth ulcers are small sores on the inside of your mouth, also known as aphthous ulcers or canker sores.

They are commonly caused by injury – such as biting your cheek, or skin snagging on orthodontic braces or a sharp tooth.

But as we’ll explore, there can be other causes.

There are three main types of recurring ulcer: minor, major and herpetiform.

Around 80% of ulcers are minor.

These are shallow, small (the size of a green pea) and round or oval-shaped, with a yellow or grey centre.

They usually take no more than two weeks to heal without treatment.

Major ulcers are larger, deeper and irregularly shaped, and take weeks or months to heal.

These often cause scarring.

Herpetiform ulcers occur in clusters of up to 100 tiny sores (the size of a matchstick head).