Post-surgical hypoparathyroidism typically presents with which electrolyte disturbance and symptoms?

• A. Hypercalcemia causing tetany
• B. Hypocalcemia causing tetany
• C. Hyperkalemia causing tetany
• D. Hyponatremia causing tetany

Answer: (B)

Damage to the parathyroid glands during neck surgery reduces parathyroid hormone, which normally raises blood calcium. Without enough PTH, calcium in the blood falls (hypocalcemia) because bone resorption, renal calcium reabsorption, and active vitamin D–mediated intestinal absorption all decrease. Low calcium makes nerve membranes more excitable, leading to symptoms of neuromuscular irritability such as tingling, muscle cramps, and tetany (involuntary muscle contractions, especially carpal and facial). Therefore, post-surgical hypoparathyroidism most commonly presents as hypocalcemia with tetany. Hypercalcemia would dampen excitability and cause weakness, not tetany; hyperkalemia and hyponatremia produce different neuromuscular or neurologic symptoms.