Tuesday, 10 August 2010

Horses, not zebras

One of my favourite medical sayings is 'If you hear hoof beats, look for horses, not zebras', first coined by the renowned American surgeon Dr. Ben Eiseman in the 1960s. It's an aphorism that was frequently drummed into me when I was training in acupuncture.

What this means is that common conditions are common, and rare conditions are rare, so a practitioner should usually resist the temptation to immediately diagnose a rare and unusual illness if there is a more common condition that matches all the symptoms.

We can all probably be grateful for this wise advice - just think if you had a GP whose first assumption was that your mild headache was a brain tumour, your nosebleed was early onset Ebola, or your rumbling tummy was a sure sign that an Alien was about to burst out of you. In almost all cases, it would scare the living daylights out of you, and be wrong as well.

In the past, the only people who usually had to have their diagnostic enthusiasm restrained were medical students. However, in the age of the Internet and Google searches, we have a new legion of cyberchondriacs, typing their symptoms onto a search bar.

And when they do so, they often find zebras, not horses. A good friend of mine was asking me last week what might be the cause of the strange bitter taste in his mouth after eating. A google search had taken him to a website where one person had attributed his symptoms to eating pine nuts.

"Well, Bob" (not his real name), I said. "Have you been eating a lot of pine nuts recently?"

"No," he replied. "Probably not that then." I said, stroking my chin. "Do you have any heartburn or acid indigestion?" "No." Have you been on the razz, sleeping poorly and eating badly recently?" "Oh yes, most definitely!"

"In that case, it's most likely to be the taste of bile, and the result of overdoing it. Western doctors used to call it biliousness, and Chinese medicine calls it Liver Fire. The first thing you should do is rest, eat properly and cut back on the booze, and only think of further treatment if it doesn't clear up."

"Damn ... cutting back on pine nuts would have been a lot easier!"

Definitely a case of dealing with horses ... not zebras.

Of course, rare conditions do sometimes happen, and the art is to recognise their unique characteristics when they do, but in most cases, the most obvious explanation is usually the right one.