THYROID FUNCTION TESTS: A REVIEW
Thyroid function tests are one of the most common endocrine panels in general practice because a good understanding of when to order them, indications for treatment are important for the optimal treatment of thyroid dysfunction. Thyroid-stimulating hormone (TSH) should be the rst test to be performed on any patient with suspected thyroid dysfunction and in follow-up of individuals on treatment. It is useful as a rst-line test because even small changes in thyroid function are sufcient to cause a signicant increase in TSH secretion. Thyroxine levels may be assessed in a patient with hyperthyroidism, to determine the severity of hyperthyroxinemia. Antithyroid peroxidase measurements should be considered while evaluating patients with subclinical hypothyroidism and can facilitate the identication of autoimmune thyroiditis during the evaluation of nodular thyroid disease. The measurement of TSH receptor antibody must be considered when conrmation of Graves’ disease is needed and radioactive iodine uptake cannot be done.