What is the most common cause of true hyperkalemia?

What is the most common cause of true hyperkalemia?

• A. Renal failure with oliguria
• B. Lab error (pseudohyperkalemia)
• C. Hemolysis from blood draw
• D. Diarrhea

Answer: (A)

Potassium balance is kept in check mainly by the kidneys, which excrete the excess in urine. When kidney function fails, especially with very low urine output, the kidneys can’t remove potassium effectively, so potassium builds up in the blood. This makes renal failure with oliguria the most common cause of true hyperkalemia. Other things on the list are confounders rather than true systemic elevations. Lab issues like pseudohyperkalemia can make a potassium reading look high without an actual body burden increase, and hemolysis during blood draw can artifactually raise the sample’s potassium. Diarrhea, on the other hand, tends to cause potassium loss, not excess.

Potassium balance is kept in check mainly by the kidneys, which excrete the excess in urine. When kidney function fails, especially with very low urine output, the kidneys can’t remove potassium effectively, so potassium builds up in the blood. This makes renal failure with oliguria the most common cause of true hyperkalemia.

Other things on the list are confounders rather than true systemic elevations. Lab issues like pseudohyperkalemia can make a potassium reading look high without an actual body burden increase, and hemolysis during blood draw can artifactually raise the sample’s potassium. Diarrhea, on the other hand, tends to cause potassium loss, not excess.