What is an oral ulcer?

An ulcer in the mouth

An oral ulcer, or an ulcer in the mouth, is a painful lesion as a result of a complete break in the epithelium of mucous membrane. The body responds to this localized defect by producing fibrins, which fills and overflows in the ‘crater’ formed by the break in mucous membrane, giving it a bubble-like protrusion from the rest of the mucosa. The presence of fibrin gives it the yellowish colour which could easily be mistaken as pus. Continue reading →