[Water-sodium homeostasis in hemodialysis - the eternal problem in nephrology practice].

The kidney is an organ that maintains the body's sodium and water balance and plays a significant role in blood pressure regulation. Chronic kidney disease (CKD) and a progressive loss of its function, among others, leads to sodium and water retention and, as a consequence, to arterial hypertension. The supply of salt and fluids delivered with the diet significantly affects the cardiovascular system's functioning particularly in hemodialysis patients.