Influenza

Your doctor will conduct a physical exam, look for signs and symptoms of influenza, and possibly order a test that detects influenza viruses.

During times when influenza is widespread, you may not need to be tested for influenza. Your doctor may diagnose you based on your signs and symptoms.

In some cases, your doctor may suggest that you be tested for influenza. He or she may use various tests to diagnose influenza. Polymerase chain reaction (PCR) testing is becoming more common in many hospitals and labs. This test may be done while you're in your doctor's office or in the hospital. PCR testing is more sensitive than other tests and may be able to identify the influenza strain.

Usually, you'll need nothing more than rest and plenty of fluids to treat the flu. But if you have a severe infection or are at higher risk of complications, your doctor may prescribe an antiviral drug to treat the flu. These drugs can include oseltamivir (Tamiflu), zanamivir (Relenza), peramivir (Rapivab) or baloxavir (Xofluza). These drugs may shorten your illness by a day or so and help prevent serious complications.

Oseltamivir is an oral medication. Zanamivir is inhaled through a device similar to an asthma inhaler and shouldn't be used by anyone with certain chronic respiratory problems, such as asthma and lung disease.

Antiviral medication side effects may include nausea and vomiting. These side effects may be lessened if the drug is taken with food.

Most circulating strains of influenza have become resistant to amantadine and rimantadine (Flumadine), which are older antiviral drugs that are no longer recommended.