In preparation for a thyroidectomy, a physician will perform a complete physical examination and take a comprehensive medical history. An EKG, chest x-ray and other heart tests may be performed, especially on patients over age 45 or those with a history of cardiac disease. Blood tests may be performed to check for bleeding disorders.

Patients who have had a change in voice or a previous neck operation will have their vocal cord function evaluated to ensure that the recurrent laryngeal nerve that supplies the vocal cord muscles is functioning normally.

If a rare form of disease known as medullary thyroid cancer has been diagnosed, patients will be evaluated for coexisting tumors of the adrenal gland known as pheochromocytomas, or for the presence of hypercalcemia (high calcium levels in the blood) or hyperparathyroidism (increased secretions of the parathyroid glands).