Vasoregulation and renal function in essential hypertension

It is well known from population studies that blood pressure tends to increase with age (Master et al., 1950; Hamilton et al., 1954; Zinner et al., 1971; Kahn et al., 1972; Buck, 1973; Kimura, 1973; Miall and Chinn, 1973), at least in Western society. Any upward deviation from this "normal" trend can thus be considered to represent a development into the hypertensive range. A hypertensive individual distinguishes himself by an earlier or steeper increase in blood pressure. Once a diagnosis of essential hypertension has been established by excluding known causes of elevated blood pressure, the follow-up of these patients is mainly based on repetitive blood pressure readings. Many studies have been carried out with respect to the epidemiology of hypertension. Such investigations provide information about the incidence and end-points of hypertension but this concerns only the easily accessible part of the disorder.