Background:Hypocalcemia is a major post-operative complication of total thyroidectomy, causing severe symptoms and increasing hospitalization time. The primary cause is secondary hypoparathyroidism following damage to or devascularization of one or more parathyroid gland during surgery.Objective:To identify the occurrence rate of post-operative hypocalcemia as an indicator of parathyroid gland function and its relation to the type of the surgical procedure of thyroidectomy whether it’s a subtotal or total thyroidectomy.Methods:One hundred and ninety patients with total and subtotal thyroidectomy were selected in this study (144 females and 46 males). The patients were divided into 2 groups, group 1 (95 patients) represent the patients with total thyroidectomy, and group 2 (95 patients) represent the patients with subtotal thyroidectomy. Serum calcium and parathyroid hormone were done pre-operatively and post-operatively for all patients with a follow-up for serum calcium for 6 months. Results:Of the total number serum calcium levels decreased from pre-operative levels in 156 patients (82%), but still within normal range (2.1-2.6 mmol/L). The overall incidence of transient hypocalcemia was 22 % (42 patients), 35 patients belong to group 1 and 7 patients to group 2, and that of permanent hypocalcemia (hypocalcemia persisted at the 6 months assessment) was 2.6 % (5 patients), 4 patients belong to group 1 and one patient to group 2. Most of the patients with hypocalcemia were asymptomatic 19.4% (n=37) and did not require calcium supplementation. Symptomatic hypocalcemia occurred in 5.2 % (n =10) patients. It was found that the overall incidence of hypocalcemia after thyroidectomy was 24.7 % (22% transient and 2.6% permanent). Conclusion:It could be concluded that, insuring the integrity of parathyroid glands is important to avoid post-thyroidectomy hypocalcemia. If incidental removal or devascularization of the parathyroid glands is noted, parathyroid auto-transplantation should be done.Keywords:Post-operative hypocalcemia, total thyroidectomy, subtotal thyroidectomy.Citation:Naji RE. Post-operative hypocalcemia among ongoing patients after total and subtotal thyroidectomy. Iraqi JMS. 2018; Vol. 16(1): 92-99. doi: 10.22578/IJMS.16.1.13