Description
The main hormone of the thyroid gland, produced by its follicular cells under the influence of thyroid-stimulating hormone (TSH). Most of it is bound to blood transport proteins. Its main functions are aimed at stimulating metabolic processes in the body (it participates in the synthesis of vitamin A in the liver, accelerates protein synthesis, controls heat production). It has a diurnal secretion rhythm with peak values in the morning hours and the lowest values in the evening. Determination of total T4 is used to assess thyroid function, diagnose hypo- and hyperthyroidism.
It is recommended to take the test in the morning hours. To obtain the most informative results, check with your attending physician for the optimal time to take the test.
Period of execution
By 9 hours. The specified time does not include the day of biomaterial collection
Biomaterial type