<prompt> Hypoparathyroidism following thyroid surgery occurs within24 hours2-5 days7-14 days2-3 weeks  <response>: Parathyroid insufficiency is due to the removal of the parathyroid glands or infarction through damage to the parathyroid end aeries; often both factors occur together. Vascular injury is probably far more impoant than inadveent removal. The incidence of permanent hypoparathyroidism should be less than 1 and most cases present dramatically 2-5 days after an operation but, very rarely, the onset is delayed for 2-3 weeks or a patient with marked hypocalcemia may be asymptomatic.Ref: Bailey and Love, page no: 815 