Thyroid hormone secretion is often modified after thyroidectomy and is not always assessed correctly. The condition is revealed less by the drop in hormonal immune reactivity than by the rapid increase in TSH and the appearance of a clinical syndrome consisting essentially of weight gain and the onset of psychological symptoms; alterations in calcium balance are not examined here. The study confirmed the behalf that these phenomena affect a large number of thyroidectomized patients and derive from a particular form of thyroid deficiency: surgical hypothyroidism. This condition should always be borne in mind after thyroid surgery and should be treated appropriately, which is only possible if hormone functions and clinical symptoms are correctly monitored.