If in doubt, Google it, doctors puzzling over a diagnosis have been told.

The internet search engine used by millions of people to find a plumber or discover what their house is worth is also pretty handy when it comes to putting a name to unusual ailments.

Embarrassing as it may seem to professionals trained for many years in medicine, Google can often come up with the right answer.

In one case described in The New England Journal of Medicine, a doctor astonished her colleagues, who included an eminent professor, by correctly diagnosing Ipex (immunodeficiency, polyendocrinopathy, enteropathy, X-linked) syndrome.

It just “popped right out” after she entered the salient features into Google, she admitted. Two Australian doctors have now put Google to a sterner test, using 26 cases from the case records section of the journal.

This is a regular feature in which the symptoms of a tricky case are described and readers are asked to come up with a diagnosis.

Hangwi Tang and Jennifer Hwee Kwoon Ng, doctors at the Princess Alexandra Hospital, in Brisbane, simply entered words from the case records into Google. The words reflected the symptoms described, and for each case they picked between three and five.

They then looked at the first three pages of the Google output — thirty items — and chose what seemed to be the most plausible of the diagnoses offered. In 58 per cent of the cases, Google came up with the right answer, or at least the same answer as given in the journal.

For example, when the case involved a 48-year-old man with multiple spinal tumours and skin tumours, the doctors searched Google by entering the words “multiple spinal tumours” and “skin tumours”. Google responded with items suggesting the man had neuro-fibromatosis type 1, the correct diagnosis.

In another case, a man lost consciousness while jogging. A search under “cardiac arrest”, “exercise”, and “young” produced the diagnosis of hypertrophic obstructive cardiomyopathy, which was also right.

Other conditions that were diagnosed successfully included Creutzfeldt-Jakob disease, gastrointestinal bleed, amyotrophy (a neurological disorder) and encephalitis (inflammation of the brain).

There were some errors. A condition deduced to be graft versus host disease turned out to be West Nile fever — quite a big difference. But the two doctors conclude that Google is well worth trying.

“Useful information on even the rarest medical conditions can now be found and digested within a matter of minutes,” they say. “Our study suggests that in difficult diagnostic cases it is often useful to ‘Google for a diagnosis’.

“Web-based search engines such as Google are becoming the latest tools in clinical medicine, and doctors in training need to become proficient in their use.”

Irritating medical television series such as House, in which a grumpy know-it-all physician played by Hugh Laurie astonishes his colleagues by his remarkable diagnostic skills, will never seem quite so impressive. How long before he is upstaged by Google?

And GPs who grumble when their patients turn up with printouts from the internet claiming that they have some obscure disease will have to be more circumspect. Having access to Google, the patients might just be right.

The doctors started their research after examining a 16-year-old water polo player with a blockage in a vein, and explaining that the cause was uncertain.

His father immediately interrupted to say: “But of course he has Paget-von Schrötter syndrome.” He had successfully Googled the symptoms and proceeded to give the doctors a mini-tutorial on the cause of the condition — huge neck muscles compressing the axillary vein — and the correct treatment.

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