Tests and diagnosis

By Mayo Clinic Staff

Your doctor will start with a physical exam that is generally the same for children and adults. The exam will include:

  • Using a lighted instrument to look at your throat, and likely your ears and nasal passages
  • Gently feeling (palpating) your neck to check for swollen glands (lymph nodes)
  • Listening to your breathing with a stethoscope

Throat swab

With this simple test, the doctor rubs a sterile swab over the back of your throat to get a sample of secretions. The sample will be checked in a lab for streptococcal bacteria, the cause of strep throat. 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 doctor will wait, however, for the more reliable, out-of-clinic lab test to determine the cause of the infection.

Other tests

  • Complete blood count (CBC). Your doctor may order a CBC 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. The profile of what's elevated, what's normal or what's below normal can indicate whether an infection is more likely caused by a bacterial or viral agent.
  • Allergy tests. If your doctor suspects your sore throat is related to an allergy, you may be referred to an allergist for additional tests.

You may be referred to an ENT doctor or other specialist if you have chronic or frequent sore throat or if there are any signs or symptoms that suggest a serious condition other than a common viral or bacterial infection.

May 07, 2013