How is tonsillitis diagnosed?

Child's throat being examined

Your doctor may examine your child’s throat and tonsils for signs of infection. Image: Ilya Andriyanov /

Your doctor may ask you some questions about your symptoms, including if you:

  • have had a cold or flu (influenza) recently
  • are taking any medicines
  • have any other medical conditions (e.g. asthma).

If your tonsillitis is caused by the flu virus, you will also have other flu symptoms such as a cough, aches and pains, and a runny nose.

A diagnosis of bacterial tonsillitis (caused by Streptococcus pyogenes) is more likely if the following symptoms are present:

  • fever (a temperature of 38.5°C or higher)
  • no cough
  • swollen glands (lymph nodes) in your neck
  • white spots or pus on your tonsils.

If your infection is caused by bacteria, you may need an antibiotic.

Your doctor may examine your throat and look at your tonsils to see if they are inflamed or if there any other signs of infection (e.g. white pus or white spots on your tonsils).

Laboratory tests

Your doctor may use a sterile cotton swab to take a small sample of cells from your tonsils and the back of your throat, which can be sent to a laboratory to find out what is causing the infection. This can help your doctor to decide if you need antibiotics or not, and if so, which antibiotic is needed to treat the infection.