the renal excretion of salt and water, thereby reducing extracellular fluid volume and cardiac output, but they also reduce intracellular sodium and calcium levels, leading to vasorelaxation and a reduction in peripheral vascular resistance with long-term use. Thiazide-type diuretics are effective antihypertensive agents in patients with normal or modestly impaired renal function as long as their dietary sodium intake does not exceed their renal sodium excretion renal function as long as their dietary sodium intake does not exceed their renal sodium excretion.