Trousseau sign is elicited by inflating a blood pressure cuff and indicates which electrolyte abnormality?

• A. Hypercalcemia
• B. Hypocalcemia
• C. Hyponatremia
• D. Hypomagnesemia

Answer: (B)

Trousseau sign demonstrates increased neuromuscular excitability caused by low calcium. When the cuff is inflated, temporary forearm ischemia triggers a painful carpopedal spasm, producing the characteristic hand posture. This reflex is a classic indicator of hypocalcemia, since low calcium lowers the threshold for nerve and muscle excitability. Hypercalcemia would dampen excitability and isn’t expected to cause this sign. Hyponatremia doesn’t typically produce this tetany, and while hypomagnesemia can contribute to low calcium, the sign is most directly tied to hypocalcemia.