Influenza is an infection caused by a virus.
It is spread from person to person by tiny drops produced during a cough or sneeze and by hand to hand contact. True influenza on the other hand, is a virus which can cause severe illness. After infection, it takes 1-3 days for symptoms to develop. Healthy people mostly have symptoms of a sore throat, dry cough, nausea and sore eyes. Fever, chills, muscle aches and pains, loss of appetite occur in more severe cases.