The thyroid profile consists of a group of tests that can be requested together to evaluate the function of the thyroid gland and as an aid in the diagnosis of their alterations. The tests included in the thyroid profile measure the quantity of thyroid hormones in the blood. Thyroid hormones travel through the blood and control or regulate the body's metabolism - how the body works and how it uses energy.
The Thrombophilia profile test usually includes:
- TSH (thyroid stimulating hormone) - used for the diagnosis of hypothyroidism and hyperthyroidism, and to monitor the treatment of thyroid disorders
- T4 (thyroxine)- is used for the diagnosis of hypothyroidism and hyperthyroidism; It can also be used to monitor the treatment
- T3 (triiodothyronine) - is used for the diagnosis of hyperthyroidism; It can also be used to monitor the treatment.
In some cases, the T3 uptake test (T3RU) can be included to calculate, along with the T4 value, the free thyroxine index. The thyroid stimulating hormone is generated in the pituitary gland and forms part of the body's feedback system to maintain stable concentrations of thyroid hormones T4 and T3 in the blood. When the concentrations of these hormones in the blood decrease, the pituitary gland is stimulated, and the TSH release occurs. For its part, TSH stimulates the production and release of T4 and T3 by the thyroid gland. When the system works properly, the production of the hormones is stimulated and inhibited to maintain an adequate concentration of thyroid hormones in the blood.
T3 and T4 are the two main hormones produced by the thyroid gland, a small organ in the shape of a butterfly attached to the trachea. Together they control the speed at which the body uses energy. The majority of T3 and T4 in blood circulates bound to proteins. The non-protein or "free" minority portions are the biologically active forms of the hormones. There are tests to measure the fractions of free T3 or T4, as well as the total T3 and T4 forms (bound and unbound portion) in blood.
Although tests that measure the total fractions of T3 and T4 have been used for many years, the results may be affected by the amount of protein available in the blood to bind to them. In contrast, the amount of free T3 and T4 is not affected by the concentration of proteins, and they seem to reflect more accurately the function of the thyroid gland. In most cases, the analysis of free T4 has replaced that of total T4. However, some guides still recommend the total T3 test.
Is any prior preparation required to ensure the quality of the sample?
For thyroid test, no special preparation is required. However, some drugs can interfere with the tests included in the thyroid profile, so it is essential to inform the doctor about any medication that is being taken.
Why do the analysis?
As an aid to evaluate the function of the thyroid gland and in the diagnosis of thyroid disorders.