Mouth ulcers are a common yet painful affliction. They usually present as round or oval sores that are found inside the mouth, developing on the lips, cheeks or tongue. Their appearance can vary; mouth ulcers can be red, white, yellow, or grey and are usually swollen. A sufferer can also experience multiple mouth ulcers at a time, which unfortunately may spread and grow. Although very uncomfortable, mouth ulcers are in most cases harmless. Without treatment, the majority of mouth ulcers will clear up within a fortnight.
There are various possible causes of mouth ulcers. To learn more about this, visit our guide to mouth ulcer causes.