title: Thyrotoxicosis. Clinical syndromes and laboratory diagnosis.
abstract: Thyrotoxicosis is not one but many syndromes, and a variety of thyroid and nonthyroid disorders can clinically simulate thyrotoxicosis. Thus, diagnosis is not always straightforward. Heat intolerance and weight loss are hallmarks of the disorder. For correct identification, abnormal elevation of triiodothyronine (T3) or thyroxine (T4), specifically the free hormone or the calculated free hormone index, must be demonstrated. Thyroidal uptake of iodine 123 helps to identify the etiology of the specific thyrotoxic syndrome.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005094:Exophthalmos / Q000473:pathology; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000139:chemically induced / Q000150:complications / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology; D007223:Infant; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications; D011247:Pregnancy; D011248:Pregnancy Complications; D013958:Thyroid Crisis / Q000209:etiology; D013960:Thyroid Function Tests; D013966:Thyroiditis / Q000150:complications