Influenza (Flu)

Influenza (flu) is a virus that spreads easily through the air by coughing and sneezing, or through physical contact of contaminated surfaces such as doorknobs and countertops. Flu can cause a high fever (usually over 101° F), cough, sore throat, headache, and muscle aches. This respiratory virus can lead to pneumonia, heart problems and sometimes death. Flu can be very serious for the elderly, pregnant women and babies who often need to be hospitalized if they get flu. Flu is also very serious for people of any age with chronic illnesses.

Symptoms include:

  • Fever.
  • Headache.
  • Tiredness.
  • Dry cough.
  • Sore throat.
  • Nasal congestion.
  • Muscle aches.

If you or someone you know has these symptoms and they are severe, contact your health care provider as soon as possible.

Flu vaccine can protect against certain types of the influenza virus. Each year the vaccine is produced based on the types of flu virus that are the most likely to cause illness during the upcoming flu season.

Flu vaccine is recommended for everyone six months of age and older. It's especially important for high-risk groups including older people young kids, pregnant women, healthcare professionals and caregivers, and people with certain medical conditions like, asthma, diabetes, heart disease, and neurologic conditions.

No flu vaccine, like any medicine, is 100 percent effective but it can help prevent severe illness, hospitalization, and death. If you get the flu after being vaccinated, it will be a much milder and shorter illness.

Scientific Term

  • Influenza

Generic Term

  • Flu

Age Groups at Risk

  • All

Fact Sheets

Vaccine Information

Vaccine Information Statements

Related Information

Department of Health:

Centers for Disease Control and Prevention: