Clinical, metabolic, and organ-specific indices of thyroid function

Presently there are a sufficient number of sensitive and specific tests of thyroid function to establish a diagnosis of thyroid disease with a high degree of precision. A variety of clinical situations, however, including but not limited to thyroid hormone resistance states, alterations in thyroid-binding proteins and nonthyroidal illness, challenge the clinician to evaluate the thyroid status of the patient beyond that which can be done with routine laboratory tests. This article reviews several clinical, cardiac, skeletal muscle, and other laboratory studies that have been suggested to complement the overall assessment of thyroid status.