Surgery is the important treatment for each type of thyroid cancer. Single or multiple parathyroid injuries or blood supply disorders may occur during the operation, resulting in dramatic decline of parathyroid hormone and hypocalcemia after operation, which is common in clinical practice. After discharge, chronic hypocalcemia can cause great physical and psychological pain to patients. Although the residual parathyroid glands can compensate after surgery in some cases, long-term negative calcium balance and postoperative hypocalcemia may cause excessive hyperplasia of the residual parathyroid glands, resulting in parathyroid hyperfunction or even hyperparathyroidism, which can lead to osteoporosis, urinary calculi, metastatic vascular calcification, and systemic abnormal migratory calcium deposits. It’s advisable to enhance the awareness of the cause and harm of the postoperative hypocalcemia, evaluate and diagnose it early, and actively intervene in every stage of before, during and after the operation and long-term follow-up, which can effectively reduce the occurrence and severity of hypocalcemia and improve the postoperative life quality and the prognosis.

Thyroid cancer is the common malignant tumor in the neck, and surgery is the important treatment measure for it. Some patients suffer from hypoparathyroidism and hypocalcemia after thyroidectomy, which will seriously affect the patient’s life quality and prognosis. This article reported a case of 42 years old female patient with hypocalcemia for 6 years after total thyroidectomy due to thyroid cancer, who still had frequent hypocalcemia with high dose of oral calcium and active vitamin D supplementation. Long-term and frequent facial and limb numbness, convulsions, epileptic-like seizures and sudden unconsciousness afflicted her due to hypocalcemia. After admission, her symptoms were obviously relieved after one week of adequate calcium supplementation through oral administration or intravenous infusion under close monitoring. Upon discharge she was able to maintain the normal level of blood calcium by decreased dose of oral calcium supplementation alone. Long-term limb numbness, convulsions, low back pain, shoulder pain, walking instability and other symptoms disappeared basically. The epileptic-like seizures did not recur. During six months of follow-up, her blood calcium was still well controlled in normal level.