Normal blood sodium levels fall within which range?

Normal blood sodium levels fall within which range?

• A. 120-130 mEq/L
• B. 135-145 mEq/L
• C. 150-160 mEq/L
• D. 100-110 mEq/L

Answer: (B)

Sodium in the blood is measured as milliequivalents per liter (mEq/L), and its normal extracellular level sits within a narrow range. The standard reference interval is 135 to 145 mEq/L. This range reflects the balance between sodium intake, kidney handling, and water distribution that keeps extracellular fluid volume and nerve/muscle function stable. When sodium dips below 135, that’s hyponatremia; when it rises above 145, that’s hypernatremia. The other ranges fall outside the normal interval and indicate disturbed sodium balance.

Sodium in the blood is measured as milliequivalents per liter (mEq/L), and its normal extracellular level sits within a narrow range. The standard reference interval is 135 to 145 mEq/L. This range reflects the balance between sodium intake, kidney handling, and water distribution that keeps extracellular fluid volume and nerve/muscle function stable. When sodium dips below 135, that’s hyponatremia; when it rises above 145, that’s hypernatremia. The other ranges fall outside the normal interval and indicate disturbed sodium balance.