Clinically, the six thyroid tests and thyroglobulin can be called the seven thyroid function tests. Patients with thyroid cancer do not necessarily have abnormalities when they undergo the seven tests of thyroid function because the nodules in the early stage of thyroid cancer are not functional and the seven tests of thyroid function are basically normal at the time of physical examination. However, thyroglobulin is indicative of thyroid cancer and some patients may have symptoms such as elevated thyroglobulin before surgery. Some patients need to take thyroxine tablets for suppressive treatment after surgery, and the amount of medication taken may directly affect the thyroid function, so the thyroid function tests may be slightly abnormal after surgery. Some patients may have more abnormalities in their thyroid tests after iodine-131 treatment, but if the values are within the normal range, there is no need to worry too much as this is normal.