Colds and flu Dr Trisha Macnair Discover how to tell the difference between the common cold and flu, including the best ways to help your child recover as quickly as possible.

In this article

What are they? What causes them?

Who's affected? What are the symptoms?

How are colds and flu treated? Further help

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

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.

The flu virus is constantly changing its structure, so new strains appear each year

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.

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.

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.

Most colds don't last long and need no specific treatment other than painkillers and simple measures such as decongestant rubs or vaporisers. Antibiotics are of no benefit. Zinc supplements may help to settle a cold more quickly.

Children with flu can be given similar treatments, with lots of rest, medicine to bring down any fever and plenty of fluids to avoid dehydration. Lowering the temperature in the room can also be helpful when someone has a fever. Specific antiviral treatments for flu are now available, but generally these are only given to those at high risk of flu complications.

If you're worried about your child's health, see your doctor. Children at high risk of flu complications are recommended to have a flu vaccination each year. This needs to be done each autumn to protect against current strains.

This article was last medically reviewed by Dr Rob Hicks in January 2008