Mouth ulcers are typically small and painful lesions that develop in the oral cavity. They can appear in different forms at various locations, such as gums, tongue, inner cheeks, lips or even the roof of the mouth.
Their occurrence is associated with discomfort while eating, drinking and speaking. They are usually red, yellow, or white in color; normally harmless; and self-healing in a week or two. But for most people, they are a great irritation.
Most mouth ulcers are harmless and heal on their own. However, you should be concerned if ulcers are large, painful, persistent (lasting more than 3 weeks), or recurring frequently. These could indicate an underlying health issue.