Hyperkalemia is defined as which of the following?

Hyperkalemia is defined as which of the following?

• A. Blood potassium less than 3.5 mEq/L.
• B. Blood potassium over 5.1 mEq/L; can cause muscle malfunction and cardiac arrest.
• C. Blood potassium around 4.0 mEq/L.
• D. High sodium level.

Answer: (B)

Hyperkalemia means there is more potassium in the blood than normal. The typical upper limit is about 5.1 mEq/L; when potassium climbs above this, it disrupts how nerve and muscle cells fire. Potassium helps set the resting membrane potential, so higher extracellular potassium makes the resting potential less negative. That changes excitability and can lead to impaired conduction, muscle weakness, and dangerous heart rhythms that can progress to cardiac arrest. So, potassium above 5.1 mEq/L with the potential for muscle problems and cardiac arrest is the correct definition. The other options describe too-low potassium, a normal range, or a non-potassium issue (high sodium), which don’t define hyperkalemia.

Hyperkalemia means there is more potassium in the blood than normal. The typical upper limit is about 5.1 mEq/L; when potassium climbs above this, it disrupts how nerve and muscle cells fire. Potassium helps set the resting membrane potential, so higher extracellular potassium makes the resting potential less negative. That changes excitability and can lead to impaired conduction, muscle weakness, and dangerous heart rhythms that can progress to cardiac arrest. So, potassium above 5.1 mEq/L with the potential for muscle problems and cardiac arrest is the correct definition. The other options describe too-low potassium, a normal range, or a non-potassium issue (high sodium), which don’t define hyperkalemia.