Diagnosis

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

The most commonly used test is called a rapid influenza diagnostics test, which looks for substances (antigens) on a swab sample from the back of the nose or throat. These tests can provide results in 30 minutes or less. However, results vary greatly and are not always accurate. Your doctor may diagnose you with influenza based on symptoms, despite having a negative test result.

More-sensitive flu tests are available in some specialized hospitals and labs.

Treatment

Usually, you'll need nothing more than bed rest and plenty of fluids to treat the flu. But in some cases, your doctor may prescribe an antiviral medication, such as oseltamivir (Tamiflu) or zanamivir (Relenza). If taken soon after you notice symptoms, 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 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. Oseltamivir has also been associated with delirium and self-harm behaviors in teenagers.

Some researchers recommend further study on both of these drugs because of uncertainty about their effects beyond a slight reduction in the time of illness. Some studies have suggested that these medications can also help reduce the severity of complications. The Centers for Disease Control and Prevention still recommends their use for some people.

An additional concern is that some strains of influenza have become resistant to oseltamivir, amantadine and rimantadine (Flumadine), which are older antiviral drugs.

Lifestyle and home remedies

If you do come down with the flu, these measures may help ease your symptoms:

  • Drink plenty of liquids. Choose water, juice and warm soups to prevent dehydration.
  • Rest. Get more sleep to help your immune system fight infection.
  • Consider pain relievers. Use an over-the-counter pain reliever, such as acetaminophen (Tylenol, others) or ibuprofen (Advil, Motrin IB, others), to combat the achiness associated with influenza. Don't give aspirin to children or teens because of the risk of Reye's syndrome, a rare but potentially fatal condition.