Today, various diseases and dangerous pathologies of the thyroid gland are quite common. Especially, this applies to the beautiful half of humanity, since according to statistics its pathology is mainly observed in women. And you have to run to doctors, get medicines, take tests for thyroid hormones to determine the usefulness and adjustment of the hormonal background. However, few people wondered what the numbers and indicators that result from this procedure mean. Let's try to figure it out.
Hormones are highly active substances that are produced by the endocrine glands, in particular the thyroid gland. Analyzes for thyroid hormones include such indicators as T3 and T4, both general and free.
The hormones T4 (thyroxine) and T3 (triiodothyronine) are classified as thyroid hormones, which are both in a free and bound state in blood serum.
In the protein-bound state, almost all hormones are found, with the exception of about one percent. In this state, they are not active, which means they cannot exert their biological effect. Depending on many different external factors, the concentration of associated hormones can sometimes vary.
Thus, barbiturates, anabolics, salicylates, androgens, furosemide and glucocorticoids lower hormone binding. A decrease in the level of associated hormones is observed with kidney damage and generalized diseases.
But during pregnancy, during the neonatal period, binding, on the contrary, increases. The concentration of protein-related hormones can change to a greater extent with the use of estrogens and oral contraceptives, infection and chronic hepatitis, HIV and cirrhosis, porphyria and some genetic diseases. And since this indicator quite often changes in one direction or another under the influence of many factors, not even related to all kinds of diseases and changes in the thyroid gland, it has already begun to be used less often.
Now, when the patient is recommended to take tests for thyroid hormones by a doctor, then only free T3 and T4 are prescribed. These are hormones that are in the blood in a free state, independent of external factors and revealing the real picture of the state and functioning of the thyroid gland. Their number should always be the same, so the number obtained tells the doctor about the development of the disease.
Hormones are the main characteristic of human reproductive function. In case of malfunction of at least one component of the entire ovary-pituitary-hypothalamus system, the reproductive system also changes, which means that the ability to conceive is reduced. Only in order to assess the state of the hormonal background of a woman, the attending physician prescribes a hormone test during pregnancy.
The efficiency of the thyroid gland is shown by the free fraction of the hormone T3, the hormone T4 is a variable form that turns into the hormone T3 if necessary. Basically, this is 30% T4. As tests for hormones show, their norm in serum is as follows: 0.03% is free T4, and 0.3% is free T3.
Hormone T3 is three times more active in biological action than T4, and its half-life is almost 6 hours, while T4 is a week. The free hormone T3 changes quite often, even during one day, its fluctuations depend not only on the person’s age, but also on chronic serious illnesses. Therefore, it is advised to take tests for thyroid hormones in most cases only to determine the level of free T4.
In modern medicine, new scientific methods of hormone tests are used. Different laboratories apply different research methods, but the most popular is the ELISA method.
It is necessary to take tests for thyroid hormones in the morning, on an empty stomach. If a person is already taking medications based on thyroid hormones, then on this day they must be canceled.