A patient with perioral numbness and positive Chvostek/Trousseau signs. Which electrolyte deficiency is indicated?

• A. Hyperkalemia.
• B. Hypocalcemia.
• C. Hypomagnesemia.
• D. Hypophosphatemia.

Answer: (B)

Low calcium levels increase the excitability of nerve membranes, leading to tingling and numbness around the mouth. The Chvostek sign (facial twitch when tapping a facial nerve) and the Trousseau sign (carpopedal spasm when a blood pressure cuff is inflated) are classic bedside indicators of hypocalcemia. Together, these findings point to calcium deficiency as the electrolyte issue. Hyperkalemia causes different symptoms such as muscle weakness and cardiac conduction changes. While severe magnesium deficiency can contribute to low calcium by impairing PTH function, the symptoms described are most directly explained by hypocalcemia. Hypophosphatemia does not typically produce this constellation of signs.