The flu is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and lungs. It can cause mild to severe illness, and at times can lead to death. The best way to prevent the flu is by getting a flu vaccine each year.

Signs and Symptoms of Flu

People who have the flu often feel some or all of these signs and symptoms:

• Fever* or feeling feverish/chills
• 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 children than adults.
Source:  www.cdc.gov