Author: OncoLink Team
Last Reviewed: April 05, 2023

What is thrush?

Thrush is a type of yeast infection. It is caused by an overgrowth of a fungus called Candida.

Thrush can affect:

  • Your tongue.
  • The lining of your mouth.
  • Your throat.
  • The lining of your esophagus (the tube that connects your throat to your stomach).

Thrush may also be called “oral thrush,” “oral candidiasis,” “oropharyngeal candidiasis,” or if it affects the lining of your esophagus, “esophageal candidiasis.”

Thrush is common in babies and children, but this article will focus on thrush in adults.

What causes thrush?

Everyone has small, safe amounts of normal fungus and bacteria in their bodies. Normally, your body can keep fungus and bacteria at safe levels. Sometimes, though, the fungus that causes thrush, Candida, can grow out of control. You may be at risk of getting thrush if:

  • You have a weakened immune system.
  • You are taking steroids, antibiotics, or are on birth control pills.
  • You are being treated for cancer. Radiation therapy and chemotherapy both raise your risk of getting thrush. Some types of cancer, like leukemia, lymphoma, and multiple myeloma come with a higher risk of thrush.
  • You are undergoing or have had a stem cell transplant.
  • You have diabetes mellitus.

What are the symptoms of thrush?

Thrush often develops suddenly. Let your care team know right away if you notice:

  • White, raised spots on your tongue, inside of your cheeks, the roof of your mouth, gum, tonsils, or back of your throat.
  • Redness and pain on the outer corners of your mouth and in your mouth.
  • Your taste changes or you cannot taste your food/drink.
  • Your mouth feels extra dry or like cotton.
  • Pain with chewing or swallowing.
  • Fever or chills.

How is thrush diagnosed?

  • Often, your provider can diagnose thrush just by looking inside of your mouth. If they brush away some of the white patches, often there is a red, sore spot underneath.
  • If it is thought that you have thrush down your throat and esophagus, they may swab your throat for a culture to be looked at under a microscope.
  • X-rays of your esophagus may be done.
  • An endoscopy (a thin tube with a lighted camera at the end of it to see down your esophagus into your stomach and small intestine) may be done.

How is thrush treated?

Since thrush is caused by a fungus, the best way to treat it is with an antifungal medication. This medication may come in the form of a tablet, a lozenge, or a liquid to swish around in your mouth before being swallowed. Be sure to take the medication for as long as it has been prescribed, even if it seems like your thrush is getting better.

How can I prevent thrush?

If you are receiving certain cancer treatments or are undergoing a stem cell transplant, your care team may give you antifungal medications before, during, and after to prevent certain infections, such as thrush.

Other things you can do to prevent thrush are:

  • Keep your mouth and teeth clean. Brush your teeth with a soft-bristled toothbrush. Do not floss without checking with your care team first.
  • Do not use mouthwashes or sprays that have alcohol in them. Talk with your care team about which ones are safe to use.
  • Visit your dentist regularly. Tell them if you are receiving treatment for cancer.
  • Limit how much sugar and yeast you eat or drink. Bread, beers, and wine can increase your risk of thrush.
  • If you smoke, quit.
  • If you use an inhaler, wash your mouth out after each use.

When should I contact my provider?

If you think you may be developing thrush, let your care team know right away. If you are receiving certain cancer treatments, your care team will look in your mouth often.

Centers for Disease Control and Prevention (CDC). (2020). Cancer patients and fungal infections. Retrieved from

Centers for Disease Control and Prevention (CDC). (2021). Candida infections of the mouth, throat, and esophagus. Retrieved from

Cleveland Clinic. (2023). Thrush. Retrieved from

National Institutes of Health: US National Library of Medicine. (2021). Thrush- Children and adults. Retrieved from

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