Which of the following is a listed cause of hyperkalemia?

• A. Renal failure
• B. Hypokalemia
• C. Anemia
• D. Hypothyroidism

Answer: (A)

Potassium balance is largely controlled by the kidneys. When kidney function is impaired, the ability to excrete potassium into the urine declines, so potassium accumulates in the blood and hyperkalemia results. The other options don’t typically cause high potassium: hypokalemia is low potassium, anemia relates to red blood cells, and hypothyroidism doesn’t directly raise potassium levels. In short, renal failure disrupts the main excretion path for potassium, making it a common listed cause of hyperkalemia.