Hyperkalemia is defined as a potassium level higher than what value?

Hyperkalemia is defined as a potassium level higher than what value?

• A. 5.0 mmol/L
• B. 5.5 mmol/L
• C. 6.0 mmol/L
• D. 5.8 mmol/L

Answer: (B)

Potassium normal range is about 3.5–5.0 mmol/L. Hyperkalemia means the level is above the upper limit of that range. In many clinical settings, 5.5 mmol/L is the threshold used to define hyperkalemia, because above this level potassium starts to meaningfully affect cardiac conduction. Elevated extracellular potassium reduces the resting membrane potential and can inactivate sodium channels, which slows conduction and can produce dangerous ECG changes (peaked T waves, QRS widening, etc.). So the value that marks hyperkalemia in this context is 5.5 mmol/L. Higher values indicate more severe hyperkalemia with increasing risk.

Potassium normal range is about 3.5–5.0 mmol/L. Hyperkalemia means the level is above the upper limit of that range. In many clinical settings, 5.5 mmol/L is the threshold used to define hyperkalemia, because above this level potassium starts to meaningfully affect cardiac conduction. Elevated extracellular potassium reduces the resting membrane potential and can inactivate sodium channels, which slows conduction and can produce dangerous ECG changes (peaked T waves, QRS widening, etc.). So the value that marks hyperkalemia in this context is 5.5 mmol/L. Higher values indicate more severe hyperkalemia with increasing risk.