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Signs & Symptoms of Flu
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Signs & Symptoms of Flu

Influenza (commonly called “the flu”) is a contagious respiratory illness caused by influenza viruses. Infection with influenza viruses can result in illness ranging from mild to severe and life-threatening complications.


  • Fever (usually high)
  • Headache
  • Extreme tiredness
  • Dry cough
  • Sore throat
  • Runny or stuffy nose
  • Muscle aches

Gastro-intestinal symptoms, such as nausea, vomiting, and diarrhea, are much more common among children than adults.


People who become infected with influenza can develop serious complications, including:

  • Bacterial pneumonia
  • Dehydration
  • Worsening of chronic medical conditions, such as congestive heart failure, asthma, or diabetes

In addition to the above, children can get sinus and/or ear infections.

At Special Risk of Complications

Certain people are at increased risk for serious complications from the flu. They include:

  • People age 65 and older
  • People of any age with chronic medical conditions
  • Pregnant women
  • Children between 6 months and 23 months

If you are at special risk from complications of flu, consult your healthcare provider when your flu symptoms begin. Your doctor may choose to use antiviral drugs to treat the flu.


Tests are available that can determine if you have the flu as long as you are tested within the first 2 or 3 days after your symptoms begin. A doctor’s exam may also be needed.

When to Call the Doctor

If you are in a high-risk group, call the doctor when you first develop symptoms, so you can be treated with anti-virus medications.

If your flu symptoms are unusually severe (for example, if you are having trouble breathing), consult a healthcare provider as soon as possible.

Please note: all information is general in nature and should not substitute seeking proper medical attention.

Contact Us

Immunization Program

Main: 303-413-7799
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