General Information

Influenza, also known as the flu, is a contagious disease that is caused by the influenza virus. It attacks the respiratory tract in humans (nose, throat, and lungs). The flu is different from a cold. Influenza usually comes on suddenly and may include these symptoms:

Tiredness (can be extreme)
Dry cough
Sore throat
Nasal congestion
Body aches
These symptoms are usually referred to as "flu-like symptoms."