HealthInfo Aoraki South Canterbury

Oral thrush

Oral thrush is a common yeast infection in your mouth. It is usually harmless, but it can be uncomfortable.

It is caused by the fungus Candida albicans, which most people carry in their mouths without any problems. Your own immune system along with harmless bacteria on your skin usually help control the amount of Candida present. But sometimes the conditions in your body change, allowing the number of Candida to multiply, causing thrush.

You can also get thrush in other parts of your body including your throat, skin, gut and vagina.

You are more likely to get oral thrush if you:

• are a pēpi or older person
• are iron deficient
• are vitamin B deficient
• smoke
• use inhaled corticosteroids such as asthma medicine
• use antibiotics for a long time
• use recreational drugs
• have diabetes
• have a weakened immune system. For example, because of HIV or cancer treatments like chemotherapy or steroids.

Symptoms of oral thrush

Typical symptoms of oral thrush include:

• a white or cream-coloured patch on your tongue, inside your cheeks or on the roof of your mouth
• red, sore or bleeding in your mouth, especially if you wear dentures
• pain or soreness in your mouth or throat
• red sores and cracks in the corners of your mouth
• difficulty eating and drinking
• an unpleasant taste in your mouth.

If you are breastfeeding and your pēpi has oral thrush, you can both have symptoms.

• For you, this can include red, sensitive or itchy nipples and pain in your breast and nipples.
• For your pēpi, this can include not feeding well and having a nappy rash.

Diagnosing oral thrush

If you think you have oral thrush, talk to your general practice team or pharmacist for advice. They will ask you questions about your symptoms and may look into your mouth.

You do not usually need to have any tests. But further testing may be needed if your doctor thinks the thrush has spread to your gut, where it can cause complications.

Treating oral thrush

Antifungal medicines that come as liquid (Nilstat), gel (miconazole) or tablets (Fungilin) will usually get rid of oral thrush. You can buy Nilstat liquid and miconazole gel from your pharmacy without a prescription. Talk to your pharmacist for advice to make sure you get the right medicine.

If you have a more severe infection, you may be prescribed fluconazole to take for 7 days.

Preventing oral thrush

Practising good oral hygiene is one of the best ways to prevent oral thrush.

• Brush your teeth twice a day or after each meal.
• Brush your gums and tongue with a soft toothbrush.
• Rinse your mouth after eating or taking medicines.
• If you smoke, stop.
• Drink plenty of water.
• If your pēpi has oral thrush, make sure anything that has been in contact with their mouth is sterilised.
• If you or your tamaiti (child) is on inhaled corticosteroids for asthma, using a spacer and rinsing your mouth with water afterwards will reduce your chances of getting thrush.
• If you wear dentures, do not wear them overnight. Clean them carefully every day and go for regular check-ups with your dentist.
• If you have diabetes, go for regular check-ups with your general practice team.

  HealthInfo recommends the following pages

• DermNet NZ – Oral candidiasis

  Information about oral thrush, risk factors for it and treatment for it.

Adapted from Healthify He Puna Wairoa as part of a National Health Content Hub collaborative. Last reviewed February 2025.

Sources

Page reference: 894639

Review key: HIDRY-74891