Oral thrush is a fungal infection caused by Candida. This fungus naturally lives in the body as part of your normal flora (the bacteria and fungi found on the skin and in the digestive system).

However, certain factors or underlying health conditions can disrupt this balance, allowing Candida to grow excessively and lead to infection.

• White patches inside the mouth, which may bleed when wiped
• A white coating on the tongue
• An unpleasant taste in the mouth
• Pain or soreness (including a sore tongue or gums)
• Cracks at the corners of the mouth
• Difficulty eating or drinking
• Reduced or altered sense of taste

Common causes and triggers

• Taking antibiotics, which can reduce healthy bacteria
• Use of steroid inhalers (especially if the mouth is not rinsed after use)
• Poor oral hygiene
• Wearing dentures, particularly if they are not cleaned properly
• Dry mouth (reduced saliva)
• Smoking

Oral thrush is more likely if you have:

• Diabetes, especially if not well controlled
• A weakened immune system (e.g. due to illness or medication)
• Conditions affecting the immune system

Other risk factors:

• Being very young (babies) or older
• Nutritional deficiencies (e.g. iron or vitamin deficiencies)
• Recent illness or general poor health