In the results of tests for hormones, among all other indicators, there is T3. By this designation is meant triiodothyronine - one of the thyroid hormones.
The physiological role of TK
Triiodothyronine, along with another thyroid hormone, thyroxine, referred to as T4, is synthesized in the tissues of the thyroid gland. The place of its formation is microscopic vesicles, follicles filled with gelatinous substance, colloid. From the protein of thyroglobulin contained in the colloid, T3 and T4 are formed under the action of specific enzymes. These hormones differ only in the iodine atom in the molecule. T3 is formed from T4 by disconnecting the "excess" iodine atom. Its activity is several times higher than T4, although the content in the blood is 3-4 times less.
T3 stimulates metabolic processes. Under its action, there is an increased breakdown of organic substances with the release of energy, memory is improved, the strength of heart contractions is strengthened, blood pressure is maintained at the proper level. It is noteworthy that in our body T3 is in two forms - in free and in plasma associated with proteins. The hormone is delivered to organs and tissues in a bound form. Then this connection is broken, and the free hormone begins to act.
The amount of free and bound hormone is the total T3. When conducting a T3 analysis, the total is 58-159 ng / dl. The share of free TK in the total amount is small - only a fraction of a percent. But it is this free T3 that provides all the physiological effects inherent in the thyroid gland. Free T3 in the analysis is measured in other units, and its value is 2.6 - 5.7 pmol / L.
Reasons for changes in analyzes
An increase or decrease in the T3 content in a blood test most often indicates thyroid diseases, including inflammation (thyroiditis), benign tumors (toxic adenoma), or malignant tumors (cancer) of the thyroid gland. It is characteristic that the same disease can occur both with an increase or a decrease in the content of T3. Much depends on the form and stage of the disease.
Thyroid disease is far from the only reason that T3 levels are out of the normal range. Among the possible causes are diseases, injuries and brain tumors, severe toxicosis (gestosis) of pregnant women, poisoning, stress, the constant use of certain drugs, mainly iodine-containing ones.
A change in the content of T3 is accompanied by such manifestations as:
- Increase or decrease in body weight;
- A uniform or nodular increase in the size of the thyroid gland;
- Fluctuation in blood pressure and palpitations;
- General inhibition, or vice versa, increased emotional excitability;
- Disruption of the stomach and intestines;
- In women - menstrual irregularities;
- In children - a lag in mental and physical development (cretinism).
The “culprit” of these manifestations is most often the thyroid gland, in which T3 is increased or decreased.
Definition of T3 in the network of Niarmedic clinics
Niarmedic laboratories are equipped with modern equipment. Thanks to this, our diagnostics are accurate results. 2-3 days before the test, it is advisable to refuse to take hormonal drugs and drugs containing iodine. The day before, it is not recommended to smoke or drink alcohol. The procedure for taking blood from a vein is performed in the morning on an empty stomach. A T3 blood test in Nyarmedik is taken on any day convenient for the patient.