Tests and diagnosis

By Mayo Clinic Staff

Oral thrush can usually be diagnosed simply by looking at the lesions, but sometimes a small sample is examined under a microscope to confirm the diagnosis.

In older children or teens who have no identified risk factors, an underlying medical condition may be the cause of oral thrush. If your doctor suspects that's the case, he or she will likely perform a physical exam and recommend certain blood tests to help find the source of the problem.

If thrush is in your esophagus

Thrush that extends into the esophagus can be serious. To help diagnose this condition, your doctor may ask you to have one or both of these tests:

  • Throat culture. In this procedure, the back of your throat is swabbed with sterile cotton. Then the tissue sample is cultured on a special medium to help determine which bacteria or fungi, if any, are causing your symptoms.
  • Endoscopic exam. In this procedure, your doctor examines your esophagus, stomach and upper part of your small intestine (duodenum) using a lighted, flexible tube with a camera on the tip (endoscope).
Aug. 12, 2014

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