Endocrine processes in the human body are regulated by the thyroid gland, through the synthesis of certain hormones by it. The thyroid hormone T4, thyroxine, has a significant effect on women’s health. The T4 rate in women ensures the correct functioning of the whole body. The production of this hormone occurs in the follicular cells of the thyroid gland, and its amount is regulated by the thyroid-stimulating hormone TSH. These two hormones are closely related, and if there are deviations from the reference values ​​of one, then the second will not correspond to the norm. 

Any disturbance in the amount of hormones causes problems in the digestive, nervous and reproductive systems.

Hormone function

Most often, at an appointment with an endocrinologist, patients ask the question: what is the T4 hormone responsible for?

Under the influence of thyroxine in the female body, the following processes occur:

• protein synthesis, which leads to oxygen saturation of all body tissues;
• the work of internal organs is normalized;
• the work of the central nervous system is activated;
• reproductive functions are normalized;
• metabolic rate is regulated;
• the work of the heart muscle returns to normal;
• the production of vitamin A in the liver is controlled.

In addition to the functions described above, T4 prevents the formation of plaques and blood clots in blood vessels, and lowers blood cholesterol levels.

Definitions of forms of thyroxine

For doctors, there are two concepts for the T4 hormone common and T4 free. The work of the thyroid gland is assessed by its content in both forms. About 99% of the total amount of thyroxine is associated with a transport protein. A change in the number of globulin cells leads to a deviation from the norm of thyroxine. At the same time, the amount of free T4 remains almost unchanged, which makes it possible to judge the state of the thyroid status.

Reference values ​​T4

The female body produces less thyroxine than the male. Therefore, it is so important to indicate the gender of the subject when taking tests in the laboratory.

It is recommended to take an analysis for the amount of T4 hormone in the morning, when its concentration in the blood is maximum. The peak of hormone production occurs from 8 am to 12 noon. By the evening, the amount of thyroxine produced decreases, and from 11 pm to 4 am its concentration in the body is minimal.

In addition to the time of day, the number of T4 is influenced by weather conditions and the time of year. In cold months, the concentration of thyroxine is much lower than in warm ones.

Although each laboratory uses its own reference values ​​for T4, the normal values ​​are:

• total T4 – from 54 to 156 nmol / l;
• free FT4 – from 10.3 to 24.5 pmol / l.

Normally, thyroxine levels remain unchanged throughout life. The exceptions are women who are in menopause and pregnant women.

With the onset of menopause, all reproductive processes in the body slow down and the need for T4 decreases to 80-100 nmol / l.

During pregnancy, the thyroid gland works in an increased mode, producing an increased amount of thyroxine.

Its maximum concentration is determined in the third trimester, and is 120-140 nmol / l. It is very important to keep track of what rate of thyroxine is produced by the body of a pregnant woman. In case of detecting problems with the thyroid gland, the doctor will prescribe medications that bring iodine-containing hormones to the correct levels.

How to prepare for analysis

Preparation for analysis includes the following:

1. Before the analysis, it is forbidden to take food – blood must be donated on an empty stomach. The best time to donate blood is from 8 am to 10 am.
2. The person who takes the analysis must be in a calm state, psychoemotional and physical influences must be excluded.
3. Before the initial examination, it is not recommended to take medications that affect the functioning of the thyroid gland.
4. For the correct interpretation of the analysis results, the laboratory assistant must be informed about the intake of all medications.

Deciphering the analysis results and possible diseases

Having received the results of the analysis, the doctor says what the norm of the hormone should be and what deviations there are.

A decrease in the level of T4 from the norm can indicate the following disorders and diseases:

• a reduced amount of iodine in the body;
• inflammatory processes in the pituitary gland;
• metabolic disorders, dystrophy;
• increased physical and emotional stress;
• the presence of benign neoplasms in the thyroid gland;
• taking medications that affect the functioning of the thyroid gland;
• surgical interventions, a history of skull trauma.

An increase in T4 levels from the norm may indicate the following disorders and diseases:

• arrhythmia;
• liver disease;
• myeloma;
• obesity;
• postpartum dysfunction.

For women, it is very important to maintain normal T4 hormone, because women’s beauty, health, the ability to become pregnant, bear and give birth to a healthy child depends on its concentration in the body. As soon as it is possible to normalize the hormone thyroxine, problems with excess weight go away, reproductive functions are restored, and overall health improves.