Medicine Acute hyponatremia becomes symptomatic at what level of serum sodium concentration? A <130mEq/L B <125 mEq/L C <120 mEq/L D <115 mEq/L 💡 Explanation Acute hyponatremia becomes symptomatic at what level of serum sodium concentration? ✓ Correct Answer: C. <120 mEq/L