Oral thrush is caused by a fungus called Candida that affects moist areas. The mouth is prone to this infection as it is always moist, or should be, in order to chew and start the digestion of food. Candida is a common organism and many people, particularly those who wear dentures, will not show any signs of thrush infection. This is because Candida does not normally overgrow because other organisms such as bacteria prevent it from rapidly growing and causing symptoms.

Infants and those that have under developed or weakened immune systems cannot fight infections easily and will often develop thrush as a result. Other people that are prone to infections will also be more likely to have thrush, such as diabetics, and those with poor nutrition or oral hygiene. Some antibiotics may occasionally cause thrush as the antibiotic has affected the helpful bacteria, as well as the infection it is treating. Other medicines, such as asthma preventer inhalers, may also cause thrush if the mouth is not rinsed out after they have been used.

Thrush usually develops as small white spots in the mouth which can become large if untreated. Infants appear to not have any other symptoms, but adults and older children often complain of pain or burning in their mouth, especially when eating or drinking.

Treatments for oral thrush are available from your community pharmacist. Adults and older children can usually use an antifungal gel or oral mixture that is applied to the mouth after eating and before bedtime.  Infants are treated successfully by ensuring that milk is washed away from the mouth after a feed by giving them a little sterilised water to drink, or they may also use an oral antifungal mixture up to four times a day.

People with oral thrush need to ensure that they keep up their oral hygiene by continuing to brush their teeth twice a day with a soft toothbrush, even though their mouth is tender. Mouthwashes and gargles may also be helpful to rinse the mouth and throat, and to ease the pain of the infection.

If you are concerned about oral thrush, your community pharmacist has specific treatments that they can sell you without a prescription. Ensure that you complete the course of treatment that your pharmacist suggests and ask them for advice in order to prevent it returning. If you are using inhalers or other medicines that make you more likely to develop thrush, your pharmacist will advise you on the correct inhaler technique or other prevention strategies. They may refer you to a doctor, if required, to manage your condition. Most people find that oral thrush is easily treated and preventable, so consult your community pharmacist for help and advice.