If you don’t think it, you won’t diagnose it

There are so many tests nowadays – blood tests, X-rays, angiograms, scans of all sorts – that they can too readily be a substitute for critically reflecting on what is really going on or, if negative, give a false impression that there is nothing seriously amiss.
The importance of the adage ''if you don’t think it, you won’t diagnose it’’, is illustrated by a woman whose complaint of dizziness on exertion warranted a referral to a cardiologist. First off she had an echocardiogram, which revealed some inflammation around the heart, known as pericarditis, which was felt to be ''non significant’’. Next up she had an angiogram of the arteries to the heart, which proved entirely normal.
All this took around six months, after which the cardiologist discharged her, even though her symptoms were unchanged. Despairing, she sought a medical opinion abroad at her own expense – and within a couple of weeks she was informed she had a positive blood test for the tick-borne infection lyme borreliosis. Though not common, this type of infection is well recognised as the cause of persistent if poorly defined symptoms. It is thus always worth ''thinking’’ about.

Source  - Telegraph