Abstract
“Essential” hypertension is related to multiple mechanisms that affect cardiac output and peripheral resistance and is a consequence of the interaction between external factors and genetic factors. Neuro-hormonal factors are essential in the pathophysiology of hypertension and among them the renin-angiotensin-aldosterone system (RAAS) has a main role in the physiological and pathological response of the cardiovascular system.
RAAS functions as an endocrine system, but also has paracrine and autocrine functions in many tissues and organs. RAAS regulates extracellular fluid volume and peripheral resistance via systemic and local actions in various tissues. RAAS also participates in endothelial dysfunction, inflammation and vascular fibrosis, cardiac fibrosis and cardiovascular remodelling, with worsening hypertension and target organ injury. Aldosterone is involved in “essential” hypertension via discrete variations in the regulation of aldosterone synthesis in the absence of confirmed primary hyperaldosteronism. A complete evaluation of these systems is needed for a thorough understanding of hypertension.