Influenza (Flu)

Influenza (flu) is a contagious respiratory illness caused by flu viruses that infect the nose, throat, and lungs. Flu can cause mild to severe illness, and at times can lead to death.
How can I Prevent the Flu? Flu Signs & Symptoms
  • Get a flu vaccine
  • Wash your hands
  • Cover your cough
  • Stay home if you're sick
  • Take antiviral medications if your doctor prescribes themCopy of PREVENT THE COLD AND FLU (Jan 2025) - Copy (2)
 People who have the flu often feel some or all of these signs and symptoms that usually start suddenly, not gradually:
  • Fever or feeling feverish/chills - It’s important to note that not everyone with flu will have a fever.
  • Cough
  • Sore throat
  • Runny or stuffy nose
  • Muscle or body aches
  • Headaches
  • Fatigue (very tired)
  • Some people may have vomiting and diarrhea, though this is more common in young children than in adults.
Diagnosing Flu Treatment
While your doctor may test you for flu, not everyone who goes to the doctor with flu-like symptoms will be tested. After evaluating you, your doctor may choose to diagnose you with flu without the need for testing based on your symptoms and his or her own clinical judgement.  Please visit Flu Symptoms & Diagnosis for more information.

If you get sick with flu, call your healthcare provider and ask about antiviral drugs.  These drugs work best when started early, such as 1 to 2 days after your flu symptoms begin.  When treatment is started within 1-2 days after flu symptoms begin, it can lessen symptoms and shorten the time you are sick. 

For people at higher risk of serious flu complications, treatment can mean the difference between milder or more serious illness possibly resulting in a hospital stay.  People at higher risk of flu complications include young children, adults 65 years of age and older, pregnant people, and people with certain medical conditions such as asthma, diabetes and heart disease.
Flu Vaccine

Everyone 6 months or older should get a flu vaccine every year.

Find a flu vaccination site near you, or see your healthcare provider pharmacist for a flu vaccination.

The best way to prevent flu and lower the risk of its complications is by getting vaccinated each year. Flu viruses change each year so you need a new vaccine every year.

The flu vaccine is not approved for children younger than 6 months old. But, infants in this age group have a higher risk of flu complications than children of any other age.  The best way to protect children younger than 6 months is to make sure members of their household and their caregivers are vaccinated.

 The best time to get vaccinated is as soon as the vaccine is available. You can still get a flu shot through the fall, winter or spring, since flu season usually peaks in February but continues through May. 

People at Higher Risk of Flu Complications

  
 

Certain people are at "high risk" of serious complications from seasonal influenza including:

  • People 65 years and older
  • Children younger than 5 years old
  • Pregnant women
  • People of any age with certain chronic medical conditions

Note: There is no recommendation that pregnant people or people with pre-existing medical conditions need to get special permission or written consent from their doctor or health care professional for influenza (flu) vaccination if they get vaccinated at a worksite clinic, pharmacy or other location outside of their physician’s office. Pregnant people should not get nasal spray flu vaccine. More information is available at Misconceptions about Seasonal Flu and Flu Vaccines.