Search and rescue?

Type 'headache causes' into your favourite search engine, and out pops everything from the common cold to inter-cranial tumours.

Go on to find potential treatments, and again, the possibilities range from taking painkillers to drilling an electrode into the brain.

These are extreme examples, but how reliable is online medical advice really? There are lots of official sites like the Cancer Association of SA and Heart and Stroke Foundation of SA, which offer sound guidance. But there are also many schemes preying on people who may already feel vulnerable or desperate, offering them a quick-fix or magic pill.

The good thing about searching for medical advice online is the wealth of information. The bad thing about searching for medical advice online is the wealth of information. You can find the most obscure of conditions, but be overwhelmed by the sheer deluge of health data available.

Dr Allan Kayle, a general practitioner based in Johannesburg, says he often has patients coming to him after they've searched for symptoms online, giving him print-outs of what they've found.

“The biggest danger is that people take one or two symptoms and make a diagnosis, and once they have a diagnosis they access all kinds of sites offering strange herbal treatments and information. It gives them the wrong impression.”

Even when searching for something relatively innocuous, like 'tension headache', surfers are bombarded with hundreds of other afflictions they should potentially be worrying about.

And often reading the list of related symptoms starts triggering anxious thoughts: “Well, I have been feeling nauseous lately, and achy... maybe I do have Lyme disease.”

This psychological leap from mild worry to full-blown panic is something easily facilitated by the nature of search engines, which aren't intelligent enough to sort diseases according to their relative likelihoods, rather than hit rates.

A 2009 study by Microsoft on so-called 'cyberchondria' shows that Web search engines have the potential to escalate medical concerns. Based on a survey of 500 people's experiences with health-related searches, the researchers found these jumps from common symptoms to serious concerns could lead to anxiety and spending unnecessary time and money on healthcare professionals.

The survey results show a significant portion of the user population use search results as an alternative for what doctors call differential diagnosis - the list of possible diseases ranked according to their corresponding likelihoods, given a patient's history and symptoms.

Three in four respondents have at least once understood the ranking of Web search results to be an indication of the likelihood of illnesses, with links to pages describing more likely diseases appearing higher up on the result page.

Take headaches, for example. The Microsoft study shows caffeine withdrawal is a far more likely cause than conditions like cerebral haemorrhage or brain tumours. However, a great deal is written about the link between headaches and these serious, rare disorders, and this abundance of information can lead both search engines and people astray, note the researchers.

Not only does this affect people directly, it also acts on search engines themselves, leading to result lists with improbable but highly concerning items near the top. In addition, click-throughs on serious disorders may lead to self-sustaining increases in the ranking of these rare cases.

“Our findings suggest that there is inappropriate escalatory risk associated with using general Web search to support differential diagnosis, and that more valuable information may come via search within expert medical sites,” say the study's authors.

But Kayle notes that most people can't access expert sources of information, as they are often locked away in academic journal sites requiring registration.

The risks involved with self-diagnosis are numerous. One danger is dismissing a complaint as something trivial when it could be serious. Another is diagnosing symptoms as grave and then panicking and trying to treat an illness you don't even have.

Kayle adds that much of the information available is spread by word of mouth and not effective. “I don't like self-diagnoses. They are based on inadequate knowledge and zero training.

“People either underestimate or overestimate what they have.”

The biggest danger is that people take one or two symptoms and make a diagnosis.

Dr Allan Kayle, general practitioner

Many sites are also not regulated by professionals, and almost anyone can knock together a credible-looking health information site. Often these sites are more focused on making a quick buck than treating an ailment, and are riddled with ads for pills and potions that promise to do just that.

“Lots of sites are funded by people trying to obtain exposure for products,” notes Kayle, going as far as to say people shouldn't access the Internet for treatments at all. “Always go to a doctor first. If you're suffering from fatigue, for example, it could be various things, from low blood pressure to anaemia. Doctors are trained to diagnose these conditions by looking at symptoms.”

The Microsoft study explains that medical experts often explore various aspects of a patient's background and symptoms, including things like gender and age, and incorporate multiple findings in their assessment. This combination of sometimes subtle signs and demographics is not easily accessible by people seeking diagnoses through a Web search.

“Unfortunately, rich sets of symptoms and detailed background information are rarely provided to search engines given the short queries input during a session. Even if such information was available, search engines do not have the ability to interpret and respond with accurate assessments,” say the researchers.

“People don't have the medical training to diagnose symptoms themselves, that's what doctors are for,” adds Kayle.

The Internet has had a profound effect on the ways people monitor and manage their health. From online disease tracking to electronic health records, many patients can now engage more directly with aspects of their wellbeing.

The London School of Economics and health insurer Bupa released a report earlier this month on the role the Internet plays in healthcare, after surveying more than 12 000 people in 12 countries.

It shows 81% searched for advice about health, medicines or medical conditions, while 39% use it to look for other patients' experiences of a condition. Also, nearly half (46%) of people who use the Internet to search for health info do so to self-diagnose.

Kayle believes the Web has aggravated people's relationship with healthcare, and given users false insights into ailments, which they should rather discuss with their doctor. “Often the information and language is over-the-top, with no understanding of the terminology.”

While accurate information can give people a better understanding of possible illnesses, other services range from marginally useful to downright misleading. One example is online pregnancy tests, many of which contain questions based on timing of menstrual cycles and intercourse to 'calculate' a result.

Another uses a 10-second scanning process claiming to check a variety of biological levels. It promises the pregnancy test results are “guaranteed”, only to explain on another page: ”Please note that we will only guarantee that you'll get a result, not that the results will be accurate.”

Kayle says using 'timing' techniques available online are nonsense. “If a woman thinks she might be pregnant, I always send a blood test to the laboratory to measure the amounts of human chorionic gonadotropin in her blood. It is manufactured by the developing embryo and not only indicates a positive or negative, but also the duration of conception.

“Timing is good for cooking,” says Kayle, but far from reliable for women seeking medical advice. “If pregnancy is suspected because a period is late, go see a doctor. There are many other diseases that can cause a missed period, and if timing is the guideline, the disease will be missed until it is really evolved.”

But the Web isn't all hype and hoaxes. One of its key elements - virtual communities - can prove beneficial in terms of support and coping. Many who've had conditions diagnosed by a real-life doctor or are undergoing treatment find dedicated forums extremely helpful. These sites often provide valuable personal accounts of symptoms, medications, and side effects, which aid understanding and help patients feel less isolated.

“The Internet can be useful,” notes Kayle, citing examples of diabetics who can access information sites to find out which foods to eat, specialists in their area or country, and other tips and advice.

According to the Bupa report, there are various trade-offs between the benefits of online research, versus the risk of misleading information, misdiagnosis and unnecessary treatments.

“However, the full potential of the Internet will only be realised if sufficient attention is paid to investment in high quality, accurate health content tailored to specific needs,” it adds.

Until that happens, English physician Peter Latham's adage applies as much to the modern medical world as it did 200 years ago: “Common sense is in medicine the master workman.”

* Speak your mind: Have you used the Internet to seek medical advice, check symptoms or to self-diagnose? Post your comments using our feedback facility.

Top 10 health info sites

Click here to see the most popular medical information Web sites during November 2010, according to Alexa.