Which value range is commonly cited as the normal serum sodium range? (numeric value)

Which value range is commonly cited as the normal serum sodium range? (numeric value)

• A. 125-135 mEq/L
• B. 130-140 mEq/L
• C. 135-145 mEq/L
• D. 145-155 mEq/L

Answer: (C)

Sodium is the main extracellular cation and sets the extracellular osmolarity that controls how water moves between body compartments. The value most clinicians and labs use as the normal reference range is 135–145 mEq/L. Keeping sodium within this window supports stable fluid balance and normal nerve and muscle function. Values below this range indicate hyponatremia, while values above indicate hypernatremia, each with distinct clinical implications. Among common options, the range that matches the standard reference is 135–145 mEq/L.

Sodium is the main extracellular cation and sets the extracellular osmolarity that controls how water moves between body compartments. The value most clinicians and labs use as the normal reference range is 135–145 mEq/L. Keeping sodium within this window supports stable fluid balance and normal nerve and muscle function. Values below this range indicate hyponatremia, while values above indicate hypernatremia, each with distinct clinical implications. Among common options, the range that matches the standard reference is 135–145 mEq/L.