Post-thyroidectomy hypocalcemia: Pathophysiology, prevention, and management strategies for the head and neck surgeon

Table 1 Definitions of hypoparathyroidism

Feature	Transient hypoparathyroidism	Permanent hypoparathyroidism
Core definition	Post-operative hypocalcemia due to parathyroid gland stunning or reversible injury, with functional recovery	Irreversible loss of parathyroid function requiring long-term management
Duration	Lasts less than 6 months after surgery	Persists for more than 6 months after surgery
Biochemical criteria	Low serum calcium with inappropriately low or normal PTH, normalizing within 6 months	Low serum calcium with an undetectable or inappropriately low PTH level persisting beyond 6 months
Treatment requirement	Requires calcium ± active vitamin D supplementation, which can be completely discontinued within 6 months	Requires calcium and active vitamin D supplementation to maintain normocalcemia beyond 6 months

PTH: Parathyroid hormone.