Which patient history raises suspicion for hypokalemia?

• A. Hyperkalemia due to kidney failure
• B. Dehydration or diuretic use
• C. High salt intake
• D. Hypermagnesemia

Answer: (B)

Recognizing factors that lead to potassium loss helps you spot hypokalemia from a patient’s history. Potassium balance is shaped by intake, renal excretion, and shifts between compartments. Diuretics cause more potassium loss in the distal nephron, and dehydration or volume depletion activates the renin-angiotensin-aldosterone system, increasing aldosterone which promotes potassium secretion in the collecting ducts. This combination makes a history of dehydration or diuretic use the strongest clue for hypokalemia. By contrast, kidney failure tends to cause high potassium (hyperkalemia); a high-salt diet doesn’t specifically drive potassium loss; and hypermagnesemia isn’t a primary driver of hypokalemia.