Total thyroxine (Total T4) (Total Thyroxine, Total T4, Serum)
The test determines the level of total thyroxine (T4), including free and protein-bound hormone fractions. Total T4 reflects thyroid hormone production and is used to assess its functional state. Applied in hypo- and hyperthyroidism diagnosis and with transport protein level changes. Recommended for chronic fatigue, drowsiness, edema, weight changes, metabolic disorders.
What the test evaluates:
- Total thyroxine concentration in blood serum
- Thyroid function considering hormonal transport protein binding
Biomaterial: Venous blood (serum)
- Draw blood fasting
- Exclude intense physical activity 24 hours before
Medications:
- If possible, do not take thyroid hormones 24-48 hours before (consult physician)
- Estrogens, oral contraceptives, iodine preparations may affect results
Inform physician of all medications taken
Recommended for:
- Suspected thyroid gland diseases
- Hormonal disorder symptoms
- Pregnancy and hormonal drug intake
- Heart rhythm disorders
Elevated total T4: may indicate hyperthyroidism, thyrotoxicosis, or elevated transport protein levels
Reduced total T4: may indicate hypothyroidism, protein deficiency, or severe systemic diseases
Note: Combination with TSH and free T4 required; endocrinologist consultation mandatory.
