This week: Could you be a cyberchondriac?

This week: Could you be a cyberchondriac?

Looking online for information on medical symptoms leads many of us to conclude that we're suffering from rare and serious illnesses, a new study suggests. It's the latest evidence of "cyberchondria".

Evidence of what?
Ever self-diagnosed early-onset dementia because you left your gloves on the bus? Decided you're infertile because you've not conceived within just three months of trying? Cyberchondria is the tendency to jump to conclusions like this based on the flimsiest of evidence after keying basic symptoms into the internet. The term was coined nearly a decade ago when it became clear that access to unmediated and sometimes incorrect medical information online fed people's tendencies to fear the worst.

Someone has studied this?
Microsoft Research looked at how people used their search engines. In what the researchers believe is the first major study into the health anxieties of people searching the net, they found one-quarter of the study sample, around 250,000 people, did at least one medical search. Of them, one-third "escalated" to seeking information specifically about rare and serious illnesses. Overall, they found around 2% of all web searches were health-related.

Why might we have this tendency to think the worst?
Eric Horvitz, an artificial intelligence researcher for Microsoft, said people tended just to look at the first couple of results and follow up from there. So, if they were looking for information on headaches and the first result mentioned "brain tumours", they would head off down that line of inquiry, even though other, much more benign, reasons for their headache were far more likely. A simple search term such as "headache" was found to be as likely to pull up hits for serious conditions as for benign ones.

People tended to treat the search engine as if it were a medical expert, said Mr Horvitz. If you key in "headache" and get five hits including the term "brain tumour" and another five hits saying "caffeine withdrawal", you might conclude - quite wrongly - that there is an equal risk of both.

How anxious do people get?
Five hundred Microsoft employees answered questions about their medical search habits. More than half said looking for information on a serious condition had interrupted their day at least once.

So are we becoming more anxious as a result of the internet?
Not necessarily. It's part of human nature to find yourself imagining the worst. Still, the Microsoft team is hoping to develop search engines for medical queries that are less likely to feed people's anxieties.

And meanwhile?
Remember: the internet is no substitute for your doctor. If you have a medical concern, he or she will give you a balanced view on it. Internet search engines are not diagnostic tools - and not all online information is reliable or complete. Another study, published last week, found that consumers who rely on the user-edited Wikipedia for information on medications are putting themselves at risk of potentially harmful drug interactions and adverse effects.

On the positive side, researchers at Nova Southeastern University in Florida found few factual errors in their evaluation of Wikipedia entries on 80 drugs. But these entries were often missing important information - for example, the fact that St John's wort can interfere with the action of the HIV drug Prezista (darunavir). "If people went and used this as a sole or authoritative source without contacting a health professional, those are the types of negative impacts that can occur," said one of the researchers.

Which sites can we trust?
One of the best is good old NHS Direct, at www.nhsdirect.org.uk.