Hypertension is a major disease of later life affecting 25% of the adult population in the industrialized world with most hypertensive individuals diagnosed as having essential hypertension. Approximately one third of these patients have elevated blood pressure due to increased sodium and water retention by the kidney resulting in suppressed plasma renin and aldosterone concentrations with high urinary potassium excretion and low plasma potassium levels. Monogenic forms of corticosteroid-dependent hypertension are rare. However, the discovery of these disorders has revealed genes whose proteins play a key role in the regulation of sodium homeostasis. The impaired function of these proteins, due to altered protein expression or the presence of inhibitors, contributes to the development of corticosteroid-dependent hypertension. This article focuses on the potential impact of environmental influences on corticosteroid-dependent regulation of sodium homeostasis and the development of hypertension.