This test measures the total amount of thyroxine (T4) in the bloodstream, including both protein-bound and free hormone fractions.
Diagnostic Value: Total T4 helps evaluate thyroid gland output and is often used alongside TSH and T-Uptake tests for a complete thyroid function picture.
Clinical Significance: Abnormal TT4 levels indicate overactive or underactive thyroid conditions. Elevated values suggest hyperthyroidism, while decreased levels point toward hypothyroidism or impaired hormone production.
Symptom Correlation: Patients may experience weight fluctuations, fatigue, changes in temperature tolerance, and altered heart rate depending on hormone excess or deficiency.
The Total T4 test provides an overview of thyroid hormone production and binding activity.