What is Influenza (The Flu)?

Definition

Influenza (flu) is a specific infection caused by the influenza virus.

The virus enters the upper part of the respiratory tract through the nose or mouth, and it may also invade the rest of the tract including the lungs.

The influenza virus specifically infects the nose, throat and lungs.

Symptoms appear after an incubation period of one to two days. The incubation period is the time between the entry of the infection into your respiratory tract and the beginning of Symptoms.

Flu is easily caught and easily spread. And although some symptoms may be cold-like, they are far more serious: headache, chills and a dry cough are rapidly joined by body aches and fever. While the fever declines on the second or third day of the illness, full recovery may take up to 6 weeks.

Transmission

The influenza virus spreads from one person to another in the spray from coughs and sneezes

or through contamination of the hand by secretions.

For more information, see also: www.who.int/mediacentre/factsheets/en/.

A bout of influenza can leave you bedridden 5 to 10 days. Influenza also lowers your body's ability to fight off other infections, which can lead to pneumonia or bronchitis. It can also worsen a current medical condition such as diabetes, lung disease, heart disease, kidney disease or cancer.

There is no such illness as 'stomach flu'. Stomach upsets are usually caused by other viruses and microorganisms.