Resistant hypertension.

Hypertension that remains above 140/90 mmHg despite the use of three antihypertensive drugs in a rational combination at full doses and including a diuretic is known as 'resistant'. The percentage of hypertensives whose condition is resistant varies in large part upon the setting: those seen in general practice show a prevalence of perhaps 5%; those seen by nephrologists, probably 50%. This paper reviews the major causes of resistant hypertension and provides specific recommendations for the evaluation and management of patients with this threatening condition.