Investigation of hypertension.

Ferguson (1975) calculated that if 5 per cent of the estimated 20 million patients with hypertension in the USA had a secondary cause, the cost of their investigation would amount to $2 billion at 1975 prices. For the majority of patients a careful clinical appraisal together with simple biochemical screening tests and a baseline ECG and chest film are adequate before embarking on therapy. For those patients in whom there are clinical or other grounds to suspect a treatable secondary cause, a wide range of modern investigative techniques are available. Even if there are no clues to a secondary cause initially, the possibility of such a cause is occasionally suggested by failure of response to triple therapy with, for example, a thiazide, a beta blocker, and a vasodilator. Whether the hypertensives are being treated in general practice or in hospital, a careful initial assessment together with regular supervision is essential to allow the identification of those with potentially curable disease.