Which statement best describes the antihypertensive effect of diuretics?

Which statement best describes the antihypertensive effect of diuretics?

• A. Promote sodium and water loss
• B. Increase potassium retention
• C. Reduce renal filtration
• D. Increase heart rate

Answer: (C)

Diuretics lower blood pressure mainly by promoting sodium and water loss. By blocking NaCl reabsorption at different parts of the nephron, they increase the amount of Na+ and water excreted in urine. The resulting fall in extracellular fluid reduces preload and cardiac output, and over time can lower peripheral vascular resistance as well. Potassium handling varies with the class—some diuretics cause potassium loss, others spare potassium—but the central antihypertensive effect is the volume reduction, not a direct reduction in renal filtration rate. Increase in heart rate is not the primary mechanism; reflex tachycardia can occur with rapid volume loss in some cases, but it does not drive the blood-pressure-lowering action.

Diuretics lower blood pressure mainly by promoting sodium and water loss. By blocking NaCl reabsorption at different parts of the nephron, they increase the amount of Na+ and water excreted in urine. The resulting fall in extracellular fluid reduces preload and cardiac output, and over time can lower peripheral vascular resistance as well. Potassium handling varies with the class—some diuretics cause potassium loss, others spare potassium—but the central antihypertensive effect is the volume reduction, not a direct reduction in renal filtration rate. Increase in heart rate is not the primary mechanism; reflex tachycardia can occur with rapid volume loss in some cases, but it does not drive the blood-pressure-lowering action.