What is the normal range for sodium in mEq/L?

What is the normal range for sodium in mEq/L?

• A. 140-150
• B. 135-145
• C. 130-140
• D. 125-135

Answer: (B)

Normal serum sodium is 135-145 mEq/L. Sodium is the major extracellular cation and helps set plasma osmolality and regulate fluid balance, which is essential for proper nerve and muscle function. Values below 135 indicate hyponatremia, risking brain swelling and symptoms like confusion or seizures. Values above 145 indicate hypernatremia, risking cellular dehydration and symptoms such as weakness or irritability. Within this 135-145 range, the body maintains stable fluid and electrolyte balance, which is why this is the standard reference.

Normal serum sodium is 135-145 mEq/L. Sodium is the major extracellular cation and helps set plasma osmolality and regulate fluid balance, which is essential for proper nerve and muscle function. Values below 135 indicate hyponatremia, risking brain swelling and symptoms like confusion or seizures. Values above 145 indicate hypernatremia, risking cellular dehydration and symptoms such as weakness or irritability. Within this 135-145 range, the body maintains stable fluid and electrolyte balance, which is why this is the standard reference.