Cold & flu health centre

Flu test: Detecting flu viruses

Most people won’t need to see a doctor if they have flu symptoms, but seeking medical help may be needed if symptoms are severe or if the person has other medical conditions that increase the risk of complications from flu.

If someone does see a doctor about flu, a flu test is not usually carried out. However, this may be recommended to help rule out other causes of the symptoms, to help monitor the spread of flu, or if a different strain of flu is suspected.

How does a flu test work?

First, your doctor will take a sample from the back of your throat or nose. To collect this sample, the doctor will use a cotton-tipped wooden stick and will simply rub the cotton tip at the back of your throat or inside your nose. The doctor will then seal the sample in a packet and send it to the lab for testing.

What does the flu test detect?

Some flu tests detect only influenza A virus. Others can detect both influenza A and influenza B viruses.