Oral thrush, also known as oral candidiasis, is a yeast infection in the mouth caused by a type of fungus called Candida albicans. The infection is not contagious, which means it cannot be passed on to others.
As well as oral thrush that occurs in the mouth, there are also several other types of thrush that affect other parts of the body. For example:
- inside the vagina (vaginal thrush)
- the nappy area of babies
- the folds of skin overlapping the nail (cuticles)
- the skin (candidal skin infection)
- the head of the penis
See the Health A-Z topic about Thrush, men for more information about fungal infection of the head of the penis.
How common is oral thrush?
Oral thrush is a common problem among certain groups of people. It often affects people who wear dentures because it can be difficult to keep dentures clean. Around 7 in 10 people who wear dentures will develop oral thrush at some stage.
Oral thrush can also occur in people with a weakened immune system, such as those with HIV and AIDS. About 9 out of 10 people with AIDS have oral thrush, which can often be severe.
Oral thrush is also common in people with type 1 diabetes and type 2 diabetes. Diabetes is a long-term condition caused by too much glucose in the blood. A recent study has shown that oral thrush is five times more common in people with severe insulin-dependent diabetes (type 1) than the population at large.
Oral thrush can sometimes affect healthy newborn babies. It can be passed on from mother to baby during labour if the mother has a yeast infection in her vagina. It can also be passed on through breastfeeding if a yeast infection is present. See the Health A-Z topic about Oral thrush in babies for more information.
Outlook
Left untreated, oral thrush can cause soreness and discomfort in the mouth. However, the condition can usually be successfully treated with antifungal medicines. See Oral thrush in adults - treatment for more information.
