, Etiology of Hypertension
• A specific cause of hypertension
established in only 10–15% of patients.
• Patients in whom no specific cause of hypertension are
said to have essential or primary hypertension.
• Patients with a specific etiology are
said to have
secondary hypertension.
• Genetic factors, psychological stress, and
environmental and dietary factors as contributing to
the development of hypertension. The heritability of
essential hypertension is estimated to be about 30%.
,Classification of hypertension on the
basis of blood pressure
JNC 7;
2003
, Normal Regulation of Blood Pressure
According to the hydraulic equation, arterial blood pressure
(BP) is directly proportionate to the product of the blood
flow (cardiac output, CO) and the resistance to passage of
blood through precapillary arterioles (peripheral vascular
resistance, PVR)
• BP = CO × PVR