Articles on Medical Diseases and Conditions

Entries Tagged ‘thyroxine’

Thyroid Tests in Hypothyroidism

Serum thyroxine. Thyroxine is frequently used as the major screening test for hypothyroidism, since the T4 level is low in most cases. There is some overlap between hypothyroid patients and normal persons in the lower part of the T4 reference range, since persons with mild, early, or subclinical disease may be inadvertently included in groups […]

Thyroid Function Tests: Free thyroxine assay

Another approach to the problem of thyroxine-binding protein alteration is to measure free T4 rather than total T4. The amount of protein-bound inactive T4 by itself has no direct influence on the serum level of metabolically active free hormone. The original Sterling technique involved separation of free from protein-bound T4 by a dialysis membrane after […]

Thyroid Function Tests: Free thyroxine index

The American Thyroid Association has recommended that the entity most commonly known as the free thyroxine index (TI, or T-7, T-12, Clark and Horn index) be renamed the free T4 index (FT4I). The FT4I was developed to correct the T4 assay for effects of thyroxine-binding protein alterations. It consists basically of the serum T4 result […]