Strep Throat

Also Known As

Throat culture

Formal Name

Group A streptococcus

Group A beta haemolytic streptococcus

Streptococcus pyogenes

This article was last reviewed on

14 March 2023.

This article waslast modified on 14 March 2023.

At a Glance

Why Get Tested?

To diagnose a possible bacterial infection of the throat (usually Streptococcus pyogenes)

When To Get Tested?

If you have a sore throat and fever and your doctor thinks it may have a bacterial cause (although most sore throats are caused by viruses and won't require antibiotics)

Sample Required?

The bacteria are tested for by throat culture. Your doctor may use a tongue depressor to hold down your tongue, and then insert a special swab into your mouth and brush it against your throat and tonsils. The swab will be sent to a laboratory, where culture is performed.

Test Preparation Needed?

No test preparation is needed. The test should be performed before antibiotics are prescribed.

On average it takes 7 working days for the blood test results to come back from the hospital, depending on the exact tests requested. Some specialist test results may take longer, if samples have to be sent to a reference (specialist) laboratory. The X-ray & scan results may take longer. If you are registered to use the online services of your local practice, you may be able to access your results online. Your GP practice will be able to provide specific details.

If the doctor wants to see you about the result(s), you will be offered an appointment. If you are concerned about your test results, you will need to arrange an appointment with your doctor so that all relevant information including age, ethnicity, health history, signs and symptoms, laboratory and other procedures (radiology, endoscopy, etc.), can be considered.

Lab Tests Online-UK is an educational website designed to provide patients and carers with information on laboratory tests used in medical care. We are not a laboratory and are unable to comment on an individual's health and treatment.

Reference ranges are dependent on many factors, including patient age, sex, sample population, and test method, and numeric test results can have different meanings in different laboratories.

For these reasons, you will not find reference ranges for the majority of tests described on this web site. The lab report containing your test results should include the relevant reference range for your test(s). Please consult your doctor or the laboratory that performed the test(s) to obtain the reference range if you do not have the lab report.

For more information on reference ranges, please read Reference Ranges and What They Mean.

What is being tested?

The test identifies Streptococcus pyogenes, known as Group A streptococcus, which are bacteria that infect the back of the throat and are a common cause for an infected and sore throat. Whilst group A Streptococcus is the commonest bacterial cause of a severe sore throat (pharyngitis), it is not the only bacterial cause and others include group C and G Streptococcus and Arcanobacterium.

Common Questions

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Throat Infection Test