Influenza begins as a local upper respiratory tract infection (everything from the neck up). Once it makes its way into the lungs it promotes cell to cell spread and transmission to other people through respiratory droplets. Flu usually lasts up to 28 days.
Basically the virus destroys the mucosal layer that protects your upper and lower respiratory tract. This damage makes the respiratory tract susceptible to subsequent bacterial invasions.
Signs & Syptoms
Adults and children experience the flu in different ways. Children’ s fever is higher and they usually have abdominal pain and vomit.