Oral thrush, also called oral candidiasis, is a fungal infection caused by an overgrowth of Candida. It is common in babies, people who wear dentures and people using antibiotics or inhaled corticosteroids. It can also occur when diabetes is poorly controlled or the immune system is weakened.
Symptoms
- White patches on the tongue, gums, palate or inside the cheeks that do not wipe away easily
- Red or sore areas that may bleed when a patch is removed
- An unpleasant taste or reduced sense of taste
- Cracks at the corners of the mouth
- Pain when eating or drinking
- Feeding difficulty or fussiness in a baby
A milk coating is often limited to a baby’s tongue and usually wipes away more easily. A healthcare professional or pharmacist can help when the diagnosis is uncertain.
Treatment and prevention
Oral thrush is treated with an antifungal medication chosen according to age, symptoms and other medications. Ask a pharmacist or clinician before treating a young baby. Complete the treatment as directed.
Clean dentures carefully and remove them at night. Brush the teeth and tongue gently and attend regular dental checks. Rinse the mouth after using an inhaled corticosteroid and use a spacer when recommended. Sterilize bottle nipples and pacifiers for babies. Repeated thrush may require assessment for an underlying cause.
When to seek medical advice
Seek advice if a baby is very young, feeding poorly or has fewer wet diapers, if treatment is not working, or if thrush keeps returning. Pain or difficulty swallowing can mean infection has spread to the throat or esophagus and requires medical assessment. People receiving chemotherapy or living with significant immune suppression should seek advice promptly.
Sources
Reviewed: 28 August 2026