Thrush is a yeast infection that can develop in the mouth and throat and on the tongue. Thrush is most common in newborns, infants, and older adults, but it can occur at any age. In healthy newborns and infants, thrush is usually not a serious problem and is easily treated and cured.

To prevent thrush from developing:

• Practice good oral hygiene, including brushing your teeth twice a day, flossing once a day, and using an antiseptic mouthwash. If you have had a previous thrush infection, replace your toothbrush to help prevent another infection. If you wear dentures, soak them each night in a chlorhexidine gluconate solution you can get from your pharmacist. You can also use a denture cleaner (such as Polident or Efferdent) that is sold in most drug or grocery stores. Scrub your dentures with water both before and after soaking them.
• Practice good hand-washing.
• If you are taking a liquid antibiotic, rinse your mouth with water shortly after taking it.
• Get treatment for conditions that increase your risk for thrush, such as diabetes, human immunodeficiency virus (HIV), or cancer.
• Use a spacer when taking inhaled corticosteroids, and rinse your mouth with mouthwash after inhaling the dose.
• For people with acquired immunodeficiency syndrome (AIDS), Listerine mouthwash may be particularly helpful.

To reduce the risk of spreading thrush to infants:

• Treat vaginal yeast infections, especially during the last 3 months of pregnancy. This will decrease your baby's risk of getting thrush during delivery. It also helps prevent spreading the infection through oral sex.
• Wash bottle nipples and pacifiers daily, and keep all prepared bottles and nipples in the refrigerator to decrease the likelihood of yeast growth.
• Do not reuse a bottle more than an hour after the baby has drunk from it because yeast may have had time to grow on the nipple.
• Boil for 20 minutes all objects that the baby puts in his or her mouth, or run them through the dishwasher.
• Change your baby's diaper soon after it is wet. A wet diaper area provides a good environment for the yeast that causes thrush to grow.
• Breast-feed your baby if possible. Breast milk contains antibodies that will help build your baby's natural defense system (immune system) so he or she can resist infection.
• Contact your doctor if you are breast-feeding and your nipples become red and sore or you have a burning pain throughout your breasts during or after nursing your baby. This may be a sign of a thrush infection in your baby.

If your baby is taking antibiotic medication for a different infection, such as an ear infection, rinse his or her mouth out with water after each dose. Antibiotic medications can disrupt the balance of bacteria in the mouth and allow growth of the yeast that causes thrush. Rinsing the mouth with water after taking an antibiotic can prevent disrupting the normal environment in the mouth.

If your baby needs medication to treat thrush, don't put the medicine dropper in the baby's mouth. Drop the medicine on a cotton swab and swab it on the affected area. Throw away the swab, and don't put anything back into the medicine bottle that could be contaminated with the yeast.