Colds and Flu.

What are they?

The common cold and flu (influenza) are very common infections of the upper respiratory tract (nose, throat, ears and sinuses).

Causes of colds and flu

Colds and flu are caused by viruses. The infections are contagious, passed on by tiny droplets and hand contact.

There are hundreds of different types of virus that can cause a cold, which explains why children get repeated colds.

Flu is caused by the influenza virus. There are three major types: A (often the cause of flu epidemics), B and C. The flu virus is constantly changing its structure, so new strains appear each year.

We don't have immunity to the new strains, which is why we can catch flu repeatedly.

Who's affected by colds and flu?

Anyone can catch a cold or flu. The peak season for colds is the colder winter months, not only because of the weather but because central heating dries out the normally moist nasal mucosa - an important defence against invading viruses.

However, you can catch a cold at any time of the year; one particular type of cold virus thrives in the summer. Flu rarely occurs outside November to February in the UK.

Some children are at particularly high risk from the complications of flu, for example those who are immunosupressed or have chronic lung or heart disease.

Cold and flu symptoms

A cold causes a stuffy or runny nose, sneezing, sore throat, cough, mild fever and tiredness, lasting two to four days.

Flu is more severe with a high fever (usually 39ºC or above), chills, headache, intense muscle pains, exhaustion, loss of appetite, cough and sometimes a blocked nose and sore throat. It may last a week or more, and possible complications include pneumonia.