Thyroidectomy can also cause which electrolyte abnormality?

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

Answer: (A)

When the thyroid is removed or operated on, the nearby parathyroid glands can be damaged or removed. Those glands make parathyroid hormone, which keeps calcium in a healthy range by increasing calcium release from bone, boosting kidney reabsorption of calcium, and helping convert vitamin D to its active form for gut absorption. If PTH drops after surgery, calcium in the blood falls—even though phosphate can rise—which is why low calcium, or hypocalcemia, is the classic electrolyte change after thyroidectomy. The other electrolyte abnormalities listed don’t arise directly from thyroid removal: potassium, sodium, or magnesium disturbances aren’t typical immediate postoperative consequences of this procedure.