Nasal Swab
Reviewed
A nasal swab is a test that checks for viruses and bacteria that cause respiratory infections. It can help diagnose the flu, COVID-19, RSV, whooping cough, meningitis, and MRSA. There are three common collection methods: anterior nares (front of nostrils), nasal mid-turbinate (back of nostrils), and nasopharyngeal (upper throat). The test may cause temporary tickling, coughing, or gagging. A negative result means no harmful germs were found; a positive result means a specific germ was found. Your provider will consider your symptoms and other factors to guide treatment.
Preparation and collection
You don't need any special preparations for a nasal swab.
Understanding this test
Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.
- A negative result means no harmful viruses or bacteria were found in the sample, but it does not rule out infection if the sample was not collected properly or if the pathogen is present in low numbers.
- A positive result means a specific type of harmful virus or bacteria was found, but your provider will consider your symptoms, medical history, and other test results to confirm the diagnosis.
- The test may not detect all possible causes of respiratory infection, and results should be interpreted by a healthcare professional.
What to do next
If you are diagnosed with an infection, follow your provider's recommendations for treating your illness. This may include medicines and steps to prevent spreading the infection.