Oral thrush is a yeast infection in the mouth, caused by a type of fungus called Candida albicans. It causes an unpleasant taste, soreness, a burning sensation on the tongue and difficulty swallowing. Oral thrush is not contagious, meaning it cannot be passed to others.
Causes of oral thrush:
Candida albicans fungus is naturally found in the mouth in small amounts. Oral thrush develops when these levels increase. This can be the result of taking certain medications (particularly inhaled steroids), poor oral hygiene, smoking, or a weakened immune system.
Your risk of developing oral thrush is also increases if you:
are on a course of antibiotics, particularly over a long period or if you are taking high doses
wear false teeth (around seven in 10 people who wear dentures will get oral thrush at some stage)
have type 1 diabetes or type 2 diabetes (oral thrush is five times more common in people with severe type 1 diabetes than the population at large)
Use an asthma inhaler to take corticosteroid medication