Cold comfort

In this country we get an average of two colds each a year - a grand total of 120 million - but do we actually know what is bugging us?

We accept colds as part of everyday life, but what if they were actually something much more serious?

Thankfully, the vast majority of colds are not sinister, but there are a few signs which might ring alarm bells.

Professor Ron Eccles, director of the Common Cold Centre at Cardiff University, says normal symptoms include a runny or blocked nose, sore throat, sneezing, headache and muscle aches and pains, accompanied by mild fever and feeling tired or rundown.

But he pointed out the common cold was not a single disease.

"It's a syndrome of symptoms which we self-diagnose as a common cold but which can be caused by perhaps half a dozen different groups of virus, with more than 200 different viruses in the groups," he said.

Prof Eccles says that, although for the majority of people a cold was nothing more than a nuisance, some viruses could be life-threatening in children and the elderly.

For example in babies, a virus called RSV can be fatal, while a cold can lead to a dangerous secondary bacterial infection in older people.

For the rest of the population, however, the key to knowing whether your cold is cause for concern lies in the respiratory side of the illness, and the duration.

Most colds last for seven to 10 days, although some can go on for as long as a month, particularly with a cough.

"If it's going on for longer than four weeks then you do perhaps need to see a GP," he said. "If you start to have difficulty breathing or can't swallow at all, then that is a serious sign."

"A cough is something colds have in common with lung cancer, but I wouldn't want everyone with a cough to think they've got cancer."

He said the main group who should be genuinely concerned about a cough was, of course, smokers.

Professor John Britton, a respiratory physician on the Royal College of Physicians' Tobacco Advisory Group, said smokers suffering from repeat chest infections could be at risk.

"The people who need to be concerned about recurrent infections are people who smoke," he said. The risk of lung cancer in life-long non-smokers is almost negligible.

"A cold usually starts with a runny nose and sore throat and that's not a problem. It's only when this develops into breathlessness and a productive cough with infected sputum that it's a more significant infection.

"If a cough does not clear up after four weeks then it might be worth getting a chest X-ray to make sure you know what infection you've got.

"The other side of trying to encourage people to seek help for symptoms is that doctors can get swamped by people who are just experiencing normal symptoms from a transient illness."

"Head cold symptoms don't matter and there's nothing anybody can do about them. You've just got to sit it out."

For anybody suffering from a particularly nasty cold, there are ways to try and fend it off.

Eating healthily, taking mild exercise and avoiding stress all help significantly, as well as natural remedies including echinacea, zinc and garlic.

On the other hand, new studies this year have suggested some cold viruses could actually help cure cancer.

Scientists discovered cold bugs behaved in a similar way to viruses which trigger a sixth of all cancers, including leukaemia and cervical cancer.

They concluded that by analysing how the cold virus worked, clues could be found about how to prevent them.

Professor Ron Hay, who headed the work, funded by the Cancer Research Campaign, said the research could help in the design of life-saving drugs."

"It would be satisfying if a nuisance virus which has plagued us for more than a century could help save lives," he said.