Oral thrush is a fungal infection in the mouth, caused by the yeast fungus candida albicans. It is common in healthy babies under two years old.
The main symptom is one or more white spots or patches in your baby's mouth (see Symptoms for more information), although some infants may not have any symptoms.
Babies rarely have oral thrush in their first week of life. It is most common in babies around four weeks old. Older babies can get it too, but this is less common.
Some babies can have repeated infections.
Oral thrush in babies is not usually linked with other illnesses or conditions. It may not bother your baby, but if their mouth is sore they may be reluctant to feed.
If your GP decides that your baby needs treatment, they will probably prescribe an antifungal medicine called miconazole, which kills the fungus in your baby's mouth (see Treatment for more information).
If you are breastfeeding, your baby can pass a thrush infection to you (see box).
