All tests · Electrolytes & Minerals · Potassium (K⁺)

Above the range

What causes a high Potassium (K⁺)?

Normal range 3.5-5 mEq/L (3.5-5 mmol/L SI). Specimen: Serum or plasma. See the full Potassium (K⁺) reference page for critical values and nursing considerations.

Above the range

Common causes of a high Potassium (K⁺)

  • Kidney failure
  • Acidosis
  • Potassium-sparing diuretics / ACE inhibitors
  • Cell lysis (hemolysis, rhabdomyolysis)

Looking for the other direction? See what causes a low Potassium (K⁺).

What is the normal range for Potassium (K⁺)?

The standard teaching reference range for Potassium (K⁺) is 3.5-5 mEq/L in conventional units, or 3.5-5 mmol/L in SI units. This value is measured in serum or plasma.

Potassium (K⁺) reference range and specimen details
SpecimenSerum or plasma
Conventional range3.5-5 mEq/L
SI range3.5-5 mmol/L
Critical value< 2.5 or > 6.5 mmol/L (life-threatening arrhythmia risk)
PanelElectrolytes & Minerals

Full details, including nursing considerations, on the Potassium (K⁺) normal range page. Reference ranges vary by laboratory, method, age, sex, and population - always use the range printed on the actual result.

Same panel

More Electrolytes & Minerals tests