Influenza

Influenza is a viral infection that affects mainly the upper respiratory tract by the influenza virus. The "upper respiratory tract" includes: the nasal passages, eustachian tubes, sinuses, pharynx, and larynx.

Infection usually lasts for about a week, and is characterized by sudden onset of high fever, aching muscles, headache and severe malaise, non-productive cough, sore throat and rhinitis.

Influenza is a common infectious condition and may occur at any age but is more common and serious in the elderly.

The virus is transmitted easily from person to person via droplets and small particles produced when infected people cough or sneeze. Influenza tends to spread rapidly in seasonal epidemics.

Most infected people recover within one to two weeks without requiring medical treatment. The condition is worse in patients with underlying lung conditions such as asthma or smoking or those with other chronic medical conditions or reduced immunity.