Can you tell the difference between a cold and the flu?

Many people confuse the terms 'cold' and 'flu' because the illnesses share some of the same features. Both are caused by viruses that infect the respiratory tract, mainly in the winter season, and both can cause symptoms such as coughing and sore throat. But here the similarity ends...

A cold is a minor viral or bacterial infection of the nose and throat and can occur in any season. Unlike treatment for flu, seeing your doctor when you have a cold is unnecessary for most healthy people, unless your illness exceeds 10 to 14 days. If it persists beyond this time you should see a GP to rule out a secondary infection, such as sinusitis or bronchitis.

The flu, short for influenza, is a viral disease of the respiratory tract - the nose, throat, bronchial tubes and lungs - and is highly contagious. It is spread through airborne droplets of moisture produced by coughs or sneezes. When you breathe these germs in through your nose or mouth, you may come down with the flu, generally within one to three days of being exposed. There are two main types of `flu: Type A and Type B, of which Type A tends to be most severe. The influenza virus mutates easily so that immunity from a previous vaccination does not fully protect against it. The immune system tends to make antibodies directed at two antigens on the surface of the virus: haemagglutinin (H) and neuraminidase (N). Changes in the shape of these two antigens means that pre-formed antibodies are less likely to lock on to them. The world therefore experiences new strains of influenza virus relatively frequently.

Recognising the symptoms
The flu's symptoms come on suddenly and include a high fever of 38 to 40 degrees Centigrade, headache, often severe aches and pains, tiredness, weakness and chest discomfort or coughing. Sometimes it involves a stuffy nose, sneezing and sore throat. A cold, on the other hand, rarely causes more than a mild fever, headache, extreme exhaustion or aches and pains. Its most obvious symptoms are a stuffy nose, sneezing, sore throat and a mild to moderate cough.