Oral thrush is an infection in your mouth. It's one type of a fungal infection called oral candida. The membranes in your mouth (oral mucosa) become infected with a fungus, usually Candida albicans. (Oral candida is also known as oral candidiasis.)
There are four common types of oral candida; these types have different signs. The four common types are:
- oral thrush - also known as pseudomembranous oral candidiasis,
- acute atrophic oral candidiasis - also known as acute erythematous oral candidiasis,
- denture stomatitis - also known as chronic erythematous oral candidiasis and chronic atrophic oral candidiasis, and
- chronic plaque-like oral candidiasis - also known as chronic hyperplastic oral candidiasis.
These infections are most commonly found in babies, people who wear dentures and elderly people. They are uncommon in other people, and can be a sign of another condition or illness that's not been diagnosed.