Epidemiology, aetiology and prognosis of hypertension

Hypertension is a common disorder. In fewer than 5% of cases there is an identifiable cause (secondary hypertension) but the great majority of patients have ‘primary’ or ‘essential’ hypertension because there is no clearly identifiable underlying cause. A number of genetic and environmental factors are known to be contributory to the development of an elevated blood pressure but a clearly defined cause is seldom identified. Irrespective of the cause, uncontrolled hypertension increases cardiovascular (CV) risk but there is now clear evidence that antihypertensive drug treatment improves patient outcome across the whole spectrum of CV risk.