Influenza or the flu is a viral infection of the upper respiratory
tract that is highly contagious, attacking anyone with lowered resistance.
In the initial stages,
the symptoms of influenza are much the same as the common cold and
include headache, fatigue and body aches.
As the virus progresses,
a fever and/or chills may be present, along with dry throat, cough,
nausea and vomiting.
of influenza include laryngitis, bronchitis and possibly pneumonia
if the infection enters the lower respiratory system.