Thyroid physiology and thyroid function testing.

The art and science of medicine has changed so much in the last 40 years, not only in the manner that physicians treat medical diseases but also in how they diagnose them. Technological advances have made it possible to have a test for almost anything. These technological advances, however, are important contributing factors to the rising cost of healthcare. More than ever, cost containment is an important element in all aspects of patient care. Minimizing costly diagnostic imaging and laboratory tests is essential in keeping healthcare costs reasonable but these tests should not be excluded at the risk of compromising patient care. For patients with thyroid disorders, the multiplicity of tests available do not make diagnoses more accurate or treatment more effective. A single test, the sensitive thyrotropin assay, most eloquently allows an organized, streamlined approach to the diagnoses and management of patients with thyroid disease. Even the most technologically advanced tests that are available cannot replace the clinical skills of the physician. Clinical acumen combined with the judicious use of diagnostic testing is one of the most important elements in diagnosing and treating a patient.