title: Thyroid function tests in thyroid and nonthyroid disease.
abstract: Modern day evaluation of thyroid disorders requires a combination of accurate clinical judgement and reliable, sensitive, and specific thyroid functions tests. Principle among the latter are thyroxine (T4) 3, 5, 3'-triiodothyronine (T3), and thyroid-stimulating hormone (TSH). Also playing an important role in special situations are free thyroxine, an assessment of bound and unbound thyroid-binding globulin, TRH stimulation, long-acting thyroid stimulator (LATS), antibodies to thyroid hormone and to thyroid receptors. Basic to interpretation of these tests in the clinical setting is a comprehension of the relationship of the hypothalamus, the pituitary, and the thyroid gland as well as a knowledge of the peripheral metabolism of thyroxine and triiodothyronine. The role of each of these laboratory tests in the evaluation of hyper- and hypometabolic states, their alteration in nonthyroid and other endocrine disorders, and the effects of environmental and physiological factors on these tests are reviewed.
mesh_terms: D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000276:immunology; D002116:Calcitonin / Q000502:physiology; D002822:Choriocarcinoma / Q000503:physiopathology; D005260:Female; D005333:Fetus / Q000502:physiology; D006505:Hepatitis / Q000503:physiopathology; D006801:Humans; D006980:Hyperthyroidism / Q000175:diagnosis; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000502:physiology; D007037:Hypothyroidism / Q000175:diagnosis; D007231:Infant, Newborn; D007674:Kidney Diseases / Q000503:physiopathology; D008297:Male; D001523:Mental Disorders / Q000503:physiopathology; D008875:Middle Aged; D011247:Pregnancy; D013312:Stress, Physiological / Q000503:physiopathology; D013954:Thyroglobulin / Q000502:physiology; D013959:Thyroid Diseases / Q000175:diagnosis* / Q000503:physiopathology; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000187:drug effects / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D013972:Thyrotropin / Q000378:metabolism / Q000502:physiology; D013973:Thyrotropin-Releasing Hormone / Q000502:physiology; D013974:Thyroxine / Q000502:physiology; D014284:Triiodothyronine / Q000378:metabolism / Q000502:physiology; D014285:Triiodothyronine, Reverse / Q000378:metabolism
chemical_list: D001323:Autoantibodies; D014284:Triiodothyronine; D014285:Triiodothyronine, Reverse; D013973:Thyrotropin-Releasing Hormone; D013972:Thyrotropin; D002116:Calcitonin; D013954:Thyroglobulin; D013974:Thyroxine