Medically reviewed by Carina Fung, PharmD, BCPPS

Tonsillitis Diagnosis

Tonsillitis can be diagnosed9 through several physical exams. You or your child’s provider is always the best person who can provide an accurate diagnosis.

Do I have tonsillitis?

Your provider will start with a physical exam that will include:

  • Using a lighted instrument to look at your throat and likely your ears and nose, which may also be sites of infection
  • Checking for a rash that may indicate scarlet fever (a complication of strep throat)
  • Gently feeling (palpating) your neck to check for swollen glands (lymph nodes)
  • Listening to your breathing with a stethoscope
  • Checking for enlargement of the spleen (to rule out mononucleosis, which can also cause tonsillitis)
  • Throat swab. With this test, your provider will swab the back of your throat for a sample to test for the presence of streptococcal bacteria.

Many clinics are equipped with a lab that can get a test result within a few minutes. However, a second more reliable test is usually sent out to a lab that can return results within 24 to 48 hours.

If the rapid in-clinic test comes back positive, then you almost certainly have a bacterial infection. If the test comes back negative, then you likely have a viral infection. Your provider may wait, however, for the more reliable out-of-clinic lab test results to determine the cause of the infection.

Your provider may also order a complete blood cell count with a small sample of your blood. The result of this test, which can often be completed in a clinic, produces a count of the different types of blood cells in your body. Abnormal counts of various blood cells types can indicate whether an infection is more likely caused by a bacterial or viral agent.

Complications from tonsillitis

Although rare, inflammation or swelling of the tonsils from frequent or ongoing (chronic) tonsillitis can cause complications such as:

  • Difficulty breathing
  • Disrupted breathing during sleep (obstructive sleep apnea)
  • Infection that spreads deep into surrounding tissue, such as in the throat and chest area (tonsillar cellulitis)
  • Infection that results in a collection of pus behind the tonsils (peritonsillar abscess)
  • Strep infection

If tonsillitis caused by group A streptococcus or another strain of streptococcal bacteria isn't treated, or if antibiotic treatment is incomplete, your child has an increased risk of rare complications such as:

  • Rheumatic fever, an inflammatory disorder that affects the heart, joints and other tissues
  • Poststreptococcal glomerulonephritis, an inflammatory disorder of the kidneys that results in inadequate removal of waste and excess fluids from blood.

Disclaimer: The information on this site is generalized and is not medical advice. It is intended to supplement, not substitute for, the expertise and judgment of your healthcare professional. Always seek the advice of your healthcare professional with any questions you may have regarding a medical condition. Never disregard seeking advice or delay in seeking treatment because of something you have read on our site. RxSaver makes no warranty as to the accuracy, reliability or completeness of this information.

If you are in crisis or you think you may have a medical emergency, call your doctor or 911 immediately.