Which statement best describes diuretics?

Which statement best describes diuretics?

• A. Decrease renal excretion of sodium and water to increase fluid volume.
• B. Increase renal excretion of sodium and water to reduce fluid volume and blood pressure, used for hypertension, heart failure, and oedema.
• C. Only used to treat infections.
• D. Primarily cause vasoconstriction.

Answer: (B)

Diuretics work by increasing the kidneys’ excretion of salt (sodium) and water, which lowers the overall fluid volume in the body and reduces blood pressure. They do this by blocking sodium reabsorption in parts of the nephron, so more salt and water stay in the urine and are eliminated. This reduced fluid volume helps decrease edema and the workload on the heart, making them useful for hypertension, heart failure, and edema. Other options don’t fit because they imply the opposite effect or a different purpose. Decreasing excretion would raise fluid volume, not lower it. Treating infections isn’t the role of diuretics, since they’re not antibiotics. Vasoconstriction would raise, not reduce, blood pressure, whereas diuretics lower BP primarily through volume reduction (and sometimes via downstream vascular effects).

Diuretics work by increasing the kidneys’ excretion of salt (sodium) and water, which lowers the overall fluid volume in the body and reduces blood pressure. They do this by blocking sodium reabsorption in parts of the nephron, so more salt and water stay in the urine and are eliminated. This reduced fluid volume helps decrease edema and the workload on the heart, making them useful for hypertension, heart failure, and edema.

Other options don’t fit because they imply the opposite effect or a different purpose. Decreasing excretion would raise fluid volume, not lower it. Treating infections isn’t the role of diuretics, since they’re not antibiotics. Vasoconstriction would raise, not reduce, blood pressure, whereas diuretics lower BP primarily through volume reduction (and sometimes via downstream vascular effects).