Leukoedema is a whiteness of the oral mucosa that may be a normal variation since some studies show that up to 90% of the population has this condition although the stringency of criteria used in some studies are questionable. However, it may also represent mild topical or surface injury to the oral mucosa that is reversible and not severe enough to cause a break (ulceration) in the mucosa or even erythema and inflammation. The injury in leukoedema is very superficial. It occurs in up to one-third of the population who do not have a tobacco habit and in up to 70% of patients who have tobacco habits. It is likely even the use of mouth washes can result in this condition.

Black patients are noted to have a higher incidence of this and it may be because the whiteness of leukoedema shows up better overlying a pigmented mucosa.

Patients do not experience any symptoms with this condition.