Why are diuretics used in CHF and what is a key risk with overdiuresis?

• A. To cure underlying HF.
• B. To relieve volume overload and symptoms; risk of hyponatremia, hypokalemia, dehydration, and renal dysfunction; monitor weight, electrolytes, kidney function.
• C. To increase cardiac output directly; risk of hypernatremia.
• D. To replace fluids.

Answer: (B)

Diuretics in heart failure are used to relieve volume overload and the associated symptoms by removing excess fluid, which lowers venous pressures and reduces edema and breathlessness. They don’t cure the underlying heart failure or directly increase the heart’s pumping ability; their main benefit is making patients feel better and function more easily by easing congestion and can help prevent hospitalizations.

A key risk with too much diuresis is losing too much intravascular volume, which can cause dehydration and reduced kidney perfusion, leading to renal dysfunction. They can also cause electrolyte disturbances, most notably hyponatremia and hypokalemia, which can have serious consequences if not monitored. That’s why careful monitoring of daily weight, electrolytes, and kidney function is essential to balance symptom relief with safety.