The Flowflex Influenza A/B Rapid Test is a rapid self test to check if you have 2 strains of the flu to help you manage your symptoms quickly. Common symptoms of the flu include a sudden onset of fever, cough (usually dry), headache, muscle and joint pain and a runny or stuffy nose. The test is intended to be used as a screening test and provides an aid in the diagnosis of acute influenza type A and B viral infections.