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

There are several tests used to diagnose flu, but not everyone who has the flu needs to be tested. In most cases, knowing that someone has the flu doesn't change the treatment plan. Doctors are more likely to use a test to diagnose flu if:

  • You're already in the hospital
  • You're at high risk of complications from the flu
  • You live with someone who is at greater risk of flu complications

Your doctor may also use a test to determine whether a flu virus is the cause of your symptoms, or if you have or are showing signs of another problem besides the flu, such as:

  • Heart problems, such as heart failure or an infection of the heart muscle
  • Lung and breathing problems, such as asthma or pneumonia
  • Brain and nervous system problems, such as encephalopathy or encephalitis
  • Septic shock or organ failure

The most commonly used test is called a rapid influenza diagnostic test, which looks for substances (antigens) on a swab sample from the nose or back of the throat. These tests can provide results in about 15 minutes. However, results vary greatly and are not always accurate. Your doctor may diagnose you with influenza based on symptoms, despite a negative test result.

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


Most people with flu, including the H1N1 flu, require only symptom relief. If you have a chronic respiratory disease, your doctor may prescribe additional medications to help relieve your symptoms.

Four Food and Drug Administration (FDA)-approved antiviral drugs are sometimes prescribed within the first day or two of symptoms to reduce the severity of symptoms and possibly the risk of complications. These are:

  • Oseltamivir (Tamiflu)
  • Zanamivir (Relenza)
  • Peramivir (Rapivab)
  • Baloxavir (Xofluza)

But flu viruses can develop resistance to these drugs.

To make development of resistance less likely and maintain supplies of these drugs for those who need them most, doctors reserve antivirals for people at high risk of complications and those who are in close contact with people who have high risk of complications.

People at higher risk of complications of the flu include people who:

  • Are in a hospital, nursing home or other long-term care facility.
  • Are younger than 5 years of age, particularly children younger than 2 years.
  • Are 65 years old or older.
  • Are pregnant or within two weeks of delivery, including women who have had pregnancy loss.
  • Are younger than 19 years of age and are receiving long-term aspirin therapy. Using aspirin during a viral illness increases the risk of developing Reye's syndrome, a rare but potentially life-threatening condition, in these individuals.
  • Have a body mass index above 40, which is defined as morbid obesity.
  • Have certain chronic medical conditions, such as asthma, emphysema, heart disease, diabetes, neuromuscular disease, or kidney, liver or blood disease.
  • Are immunosuppressed due to certain medications or HIV.
  • Are of American Indian or Alaska Native heritage.

Lifestyle and home remedies

If you develop any type of 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), cautiously. Also, use caution when giving aspirin to children or teenagers.

Though aspirin is approved for use in children older than age 3, children and teenagers recovering from chickenpox or flu-like symptoms should never take aspirin. This is because aspirin has been linked to Reye's syndrome, a rare but potentially life-threatening condition, in such children.

Remember, pain relievers may make you more comfortable, but they won't make your symptoms go away faster and they have side effects. Ibuprofen may cause stomach pain, bleeding and ulcers. If taken for a long period or in higher than recommended doses, acetaminophen can be toxic to your liver.

Oct. 20, 2020
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