Oral thrush

Also called Mouth thrush or Oral candidiasis

Oral thrush is an infection in the mouth caused by a fungus called Candida. It is common in babies and older people, and in people who wear dentures, use steroid inhalers, take antibiotics, have diabetes or have a weakened immune system. It is not usually serious.

Last updated Nov 9, 2026

What it is

It is usually treated with antifungal gel, drops or tablets. Treating any cause, such as badly fitting dentures, helps stop it coming back.

Rinsing your mouth after using a steroid inhaler and keeping dentures clean can help prevent it.

Common signs

  • White patches in the mouth that may wipe off
  • Redness or soreness inside the mouth
  • Cracks at the corners of the mouth
  • An unpleasant taste or loss of taste
  • Pain when eating or drinking

How it is usually diagnosed

  • Looking inside the mouth
  • Sometimes a swab
  • Blood tests if it keeps coming back

Records worth keeping

Keeping these together makes each appointment easier, especially when you see a new doctor:

  • Swab results
  • Prescriptions
  • Dentist or GP notes

Questions to ask your doctor

  • What might be causing it?
  • How long should the treatment take?
  • What should I do if it comes back?

When to get help right away

Call 112 or go to the nearest emergency department if you have:

  • Difficulty swallowing, or thrush with a weakened immune system that is getting worse: see a doctor the same day

This page is general information. It is not a diagnosis and does not replace a doctor who knows your history. Medfold keeps your records organised; it does not interpret them.

Sources