What is influenza?
Influenza, also called the flu, is a contagious respiratory illness caused by influenza viruses. It can cause mild to severe illness and at times lead to death. Influenza viruses cause disease among all age groups. Rates of infection are highest among children. Yet, rates of serious illness and death are highest among the elderly, children less than two, and persons of any age who have medical conditions that place them at increased risk for influenza complications.
The best way to prevent the flu is to get a seasonal flu vaccination each fall.
Every year in the United States, on average:
- Five to 20 percent of the population gets the flu
- More than 200,000 people are hospitalized from flu complications
- Nearly 36,000 people die from flu
Symptoms of the flu include:
- Fever (usually high)
- Extreme tiredness
- Dry cough
- Sore throat
- Runny or stuffy nose
- Muscle aches
- Stomach symptoms, such as nausea and diarrhea, can occur, but are more common in children
Complications of flu can include bacterial pneumonia, dehydration, and worsening of chronic medical conditions such as asthma.
How Flu Spreads
Flu viruses are spread from person-to-person through respiratory droplets which occur during coughing, sneezing or touching surfaces contaminated with the virus and then touching your mouth or nose. Adults can spread the flu up to one day before symptoms develop and three to five days after becoming sick. So you can pass on the flu to someone else before you know you are sick, as well as while you are sick.