Influenza (or “flu”) is an infection of the respiratory tract (nose, throat, wind pipe and lungs) caused by the Influenza virus. It is important to realize that it is incorrect to call any runny nose or sore throat ‘the flu’ as these symptoms can be caused by a large number of different viruses and are usually mild. Influenza, on the other hand, is a more severe disease which kills hundreds of elderly and young children each year. Compared to the common cold, in influenza, weakness, increased tiredness, muscle aches, headaches and high fevers with sneezing, are more prominent.