Analysis for TSH: what is it, indications, norm and interpretation. How to take a blood test for thyroid hormones T3 f T4 f TSH T3 T4 TSH hormones are responsible

Functions of organs and various systems human body depends on work thyroid gland. Very many diseases are "obliged" to its pathology. To determine how this vital organ works, a blood test is prescribed for the presence of thyroid-stimulating hormone, triiodothyronine and thyroxine.

TSH, produced by the pituitary gland (a gland in the lower part of the brain), performs a maintenance function by controlling the amount of T3 and T4 that affect energy production in the human body. As soon as the content of the hormones T3 and T4 in the blood is below normal, TSH synthesis increases, depending on the hormone secreted by the hypothalamus. If the function of the pituitary gland is disturbed, there is a change in the concentration of thyroid-stimulating hormone. Hypothalamic disease lowers or increases the level of thyreoliberin (regulator of thyroid-stimulating hormone secretion). If its level is elevated, hyperthyroidism develops, since insufficient or excessive amounts of hormones enter the bloodstream for normal work.

Hyperthyroidism (thyrotoxicosis) or clinical syndrome is a consequence of an increase in the blood of hormones actively produced by the thyroid gland, as a result of which metabolic processes are accelerated. If the level of hormones is below normal, there is a slowdown in metabolic processes, forming a disease of hypothyroidism.

Analysis

The thyroid gland is the most sensitive human organ that is negatively affected by its functioning. Therefore, the sooner the smallest deviations are identified, the better. A positive attitude, excellent health, the desire to live an active life, will guarantee its normal operation.

If you suspect a violation in the thyroid gland, an appointment is made for the analysis of all three hormones - TSH, T4 and T3. For people who are already undergoing treatment, these tests are mandatory, since they determine the state of the disease at a certain stage of its development.

The basis for the delivery of the analysis may be certain symptoms. For example, with an increase in the main hormone, a person feels weakness, irritation, nausea or even vomiting may appear, outwardly this may affect the skin - it becomes pale, has no healthy look. There is an increase in weight that cannot be lost, constipation, drowsiness or lack of sleep, fatigue, body temperature can drop to 35 degrees, and during pregnancy there is a noticeable thickening of the neck.

When the level of the main TSH decreases, there is a feeling of constant hunger, diarrhea, trembling in the body, the temperature sometimes rises, and a headache. A competent endocrinologist will help establish an accurate diagnosis and prescribe treatment. Self-medication is dangerous.

The category of people over the age of 40 also requires examination. This is the age at which health problems can not be immediately identified as insidious thyroid diseases do not make themselves felt from the very beginning of their development. To maintain health, it is advisable to regularly take a blood test.

Diseases

The content of this hormone depends on age.

If the content of TSH is lowered, you should look for the "root of evil" in the presence of diseases such as:

• diffuse toxic goiter or thyrotoxic adenoma (Plummer's disease),
• autoimmune thyroiditis,
• perhaps a mental illness or an extremely depleted body gives such an indicator.

An increased level is observed when:

• hypothyroidism (primary or secondary),
• thyroiditis hashimoto,
• pituitary tumors,
• syndrome of unregulated production of TSH,
• insufficient function of the adrenal glands,
• thyrotropin-secreting lung tumors,
• preeclampsia,
• mental illness,
• lead poisoning,
• some medicines.

Signs of deviations

Finding a disease using the analysis of thyroid-stimulating hormone is still not enough to establish an accurate diagnosis, since it changes depending on the processes occurring in the body of any person, therefore, an analysis of two others, derivatives - thyroxine and triiodothyronine, is prescribed.

Normally, triiodothyronine in the blood is contained in an amount of 1.08-3.14 nmol / l. If the indicator is increased, then you should think about possible violation in the work of the thyroid gland. In this case, Pendrer's syndrome, thyroid adenoma, possibly nephrotic syndrome, hyperthyroidism, etc., begin to develop. Low rate hormone is suspected of developing kidney failure or severe iodine deficiency, hypothyroidism and so on.

The normal concentration of thyroxine in a woman is 71-142 nmol / l, for a man - 59-135 nmol / l. If this indicator is increased, perhaps we are talking about pathology. The list of suspected diseases includes:

• nephrotic syndrome,
• thyrotoxic adenoma,
• thyroxin-binding globulin levels may be reduced,
• chronic development of diseases of the liver or thyroid gland is possible.

Deviation

According to the results of the tests, the doctor can draw the following conclusions:

• At the norm of T4 and T3, an increased concentration of TSH indicates the initial stage of the development of hypothyroidism.
• At normal T4 levels and normal or reduced content T3, there is an increase in the limiting concentration of TSH, indicating hypothyroidism.
• Low percentage of TSH normal level two other hormones raises the suspicion of the initial stage of hyperthyroidism.
• Low TSH in the blood, with normal or elevated levels of two other vital hormones, means there is a sign of hyperthyroidism.
• With a normal or simultaneous decrease in T4 and T3 in the blood, TSH may be normal, which confirms the presence of secondary hypothyroidism.
• With normal TSH, a simultaneous increase in the other two substances, there is resistance (resistance) to thyroid hormones.

Normally contained in the body: thyroid-stimulating hormone - 0.4-4.0 mU / l, free triiodothyronine - 2.6-5.7 nmol / l, free thyroxine - 9.0-22.0 nmol / l.

Features of the hormonal background in pregnant women

It should be remembered that in pregnant women there is always a decrease in thyroid-stimulating hormone, since the baby needs iodine-containing substances until his thyroid gland is formed. At the same time, the mother's thyroid gland increases the synthesis of these hormones by reducing the production of thyrotropin by the pituitary gland. However, the level of the main hormone close to zero should alert. This may mean the presence of failures in the body, but the symptoms of these failures are similar to the symptoms of toxicosis caused by pregnancy. Therefore, it is necessary with the help of analyzes to control the presence or absence of pathology in order to detect it in time.

Hormonal imbalance leads to dangerous consequences, provoking serious diseases, therefore, at the first sign of violations, you should consult a specialist for a thorough examination. Blood testing for thyroxine content should be done once every six months.

TSH is short for thyroid-stimulating hormone, a pituitary hormone that stimulates the thyroid gland. It is one of the main hormones in the human body and is responsible for the full functioning of a very important organ - the thyroid gland. The hormone is produced in the brain by the pituitary gland. The substance is a stimulant for the release of thyroxine and triidthyronine by the thyroid gland - hormones that are responsible for the full functioning of the main systems in the body, as well as proper fat metabolism. For this reason, a violation in the production of these hormones threatens serious health consequences.

In order to detect violations, an analysis is shown blood TSH. Such an examination is most often necessary for women, who are 10 times more likely than men to suffer from disorders in the pituitary gland and thyroid gland. In the vast majority of cases, blood for the determination of TSH hormones is taken simultaneously with blood for the detection of thyroid hormones. The endocrinologist is engaged in deciphering the TSH blood test. According to its results, he prescribes treatment to the patient with the use of certain drugs. As a rule, with properly selected therapy, it is possible to normalize the patient's condition in a short time.

What effects does TSH have on the body?

In addition to regulating the functioning of the thyroid gland, the hormone also affects the entire body as a whole. The substance is necessary for the following processes to take place:

• full production of proteins;
• maintaining proper heat exchange;
• activation of metabolic processes;
• qualitative synthesis of nucleic acids;
• qualitative synthesis of phospholipids;
• proper formation of red blood cells;
• proper glucose metabolism;
• proper absorption of iodine by thyroid cells;
• stimulation of adenylate cyclase.

Also, without the action of thyroid-stimulating hormone, full-fledged muscle activity, full-fledged thinking, oxygenation of tissues, and maturation of eggs are impossible.

The norm of the hormone in the blood by age

When a biochemical blood test is performed, TSH violations are determined based on generally accepted norms. Depending on age, the rate of the hormone changes as follows:

Sometimes in different laboratories in the analyzes of the same person there may be a discrepancy of 0.2, which is considered the norm. This deviation is usually associated with the reagents that are used to test the blood for thyroid-stimulating hormone.

What diseases cause an increase in the hormone

There are many reasons for raising hormones. A blood test for TSH may be elevated in the following cases:

• removal of the thyroid gland;
• treatment of thyroid diseases with radioactive iodine;
• autoimmune diseases, in which the cells of the thyroid gland are destroyed by the cells of the body, taking healthy tissues for pathological ones;
• traumatic injuries of the thyroid gland;
• especially severe iodine deficiency;
• cancerous tumors that thyroid gland;
• insufficiency in the work of the adrenal glands of a congenital nature;
• excessive function of the hypothalamus;
• benign neoplasms of the pituitary gland;
• violation of the sensitivity of body tissues to hormones secreted by the thyroid gland;
• heavy viral infections;
• severe stress;
• severe physical overload;

In the event that a person is prescribed treatment with drugs that can disrupt hormone levels, it is shown to regularly test for TSH hormones. This will allow timely detection of violations and carry out the necessary adjustment of the state.

Symptoms of elevated TSH

A number of signs indicate that the hormonal background is elevated. It is necessary to take an analysis of TSH in the following cases, when there are:

• weight gain;
• swelling of the lips, eyelids, tongue and limbs;
• frequent chills;
• general muscle weakness;
• depressive states;
• frequent insomnia;
• memory impairment;
• slow heart rate below 55 beats per minute;
• increased fragility of nails;
• excessive hair loss;
• excessive pallor of the skin;
• tendency to constipation;
• special soreness and scarcity of menstruation;
• loss of sexual desire;
• mastopathy.

This symptomatology is a direct indication for visiting a doctor, who will give a referral for a blood test for TSH. All symptoms at once appear only if the level of hormones is disturbed very strongly. With mild violations, only a part of the signs and in a slight intensity appear. Despite the fact that at this moment the condition does not cause severe discomfort, it should not be ignored.

It is easy to guess that the pituitary gland, by increasing the synthesis of TSH, is trying to “force” to produce T3 and T4, which are clearly not enough. Therefore, first of all, a high level of TSH speaks of a decrease in thyroid function - hypothyroidism, or myxedema.

Causes of low TSH

The causes of low hormones can be different. Pathology occurs much less frequently than the previous one, but still it should not be forgotten. Most often, low TSH is observed with a significant increase in the level of thyroid hormones. In this case, a blood test is taken for TSH and many other hormones. Pathology is most often caused by the following factors:

• Graves' disease and hyperthyroidism (thyrotoxicosis);
• tumor formations of the thyroid gland;
• brain tumors;
• cancer metastasis to the pituitary gland;
• traumatic brain injury;
• inflammation of the brain;
• traumatic conditions in which acute pain is present;
• diseases accompanied by acute pain;
• taking a number of medications.

It is not uncommon for TSH deficiency to be caused by taking medicines- analogues of thyroid hormones. For this reason, quite often the patient is prescribed a blood test for TSH hormones during the treatment period.

Symptoms of a low TSH level

It is also necessary to take an analysis for TSH with symptoms of it reduced level. The main ones are:

• weight loss;
• goiter formation;
• elevated body temperature up to a maximum of 37.5;
• increased appetite;
• quickened chair;
• tachycardia;
• heart failure;
• increased fragility of bones;
• neurasthenic disorders in the work of the psyche;
• panic attacks;
• severe muscle weakness;
• insufficiently frequent blinking;
• wide-open eyes;
• sensation foreign body in the eyes, bulging eyes;
• increased dryness of the mucous membrane of the eye;
• increased dryness of the skin.

All of these symptoms are indicative of hyperthyroidism. An excess of thyroid hormones leads to the fact that there is no need to stimulate it, and the secretion of TSH simply stops. These symptoms are an indication for a blood test for thyroid hormones and TSH (tsh). It is not necessary to refuse blood tests for hormones in this state, as this can lead to the fact that the onset of the development of a serious pathology in a severe form will be missed, the treatment of which will be extremely difficult and difficult. The need for testing should always be determined by the doctor, not the patient.

Indications for analysis on TSH

Biochemistry - a blood test for TSH hormones is prescribed for many reasons. The need to take a blood test arises in the following cases:

• suspected hypothyroidism with latent course;
• amenorrhea;
• female infertility in the normal state of the genital organs;
• baldness;
• frequent depression;
• deterioration of muscle function (especially the muscles of the limbs);
• a significant decrease in body temperature for no apparent reason;
• lag in sexual development;
• mental retardation;
• decreased libido;
• impotence;
• arrhythmia in the absence of pathology of the heart muscle;
• fatigue.

In the event that the doctor suspects the need to conduct hormone therapy, he appoints or nominates the analysis on TTG. After examining the results of the tests, the specialist selects the optimal treatment for the patient.

Preparation for the delivery of the analysis

Knowing what TSH is, it is very important to properly prepare to take tests for TSH. Since so many factors influence the hormonal background in the human body, if the recommendations are not followed, it will be impossible to understand what the result of the study says. The results of the analysis are deciphered based on the fact that the patient followed certain recommendations the previous day before blood sampling. How to pass the analysis correctly, informs the doctor giving him a referral. If this is not done, information on how to properly donate blood for TSH analysis can be obtained from the nurse who takes the material.

First of all, eating food affects the hormone in the blood, and therefore, when preparing to take tests for hormones, you should stop eating food at least 12 hours in advance. Also, in order for the test to show TSH correctly, 5 days before it, they refuse products that negatively affect the hormonal system, and therefore exclude fatty foods, alcohol, lemonades and fast food. If this is not done, then the values ​​\u200b\u200bthat the result of the TSH analysis shows will not correspond to the real picture and you will have to take the analysis for TSH again.

For cigarette lovers, the question of how long you can not smoke before donating blood is relevant. TSH hormone. Ideally, of course, avoid bad habit a few days before the sampling, but if this is not possible, 4 hours before the procedure will be enough, which will be carried out without a cigarette.

When an analysis is done, there are no restrictions on the liquid, unless, of course, a person drinks only pure, non-carbonated water. You can drink it in any volume and even immediately before taking a blood test. In the event that the desire to eat before the procedure is irresistible, it is allowed to drink a cup of warm, weak green tea. In such quantity, it will not change the picture of the blood, but will eliminate the unpleasant feeling of hunger. This drink, but already strongly brewed, is recommended after blood sampling in the event that weakness and dizziness are felt after it.

When a person is preparing for an analysis, for a period of 5 days before it, it is necessary to refuse, if possible, drugs, as they can disrupt the picture, which means the results are unreliable and, as a result, the further treatment is incorrect. If it is impossible to refuse medicines, there is still a way how to correctly pass the TSH test. In such a situation, the rules for surrender biochemical analysis establish the need to inform the doctor who takes the blood, what funds and in what volume were taken and how long before the analysis, which means that the result will be determined taking into account the possible error according to a special table. Most often this applies to adults taking life-saving drugs.

Special attention should be paid to taking material for analysis from women. They are often interested in the question of how to donate blood during menstrual cycle. This state does not affect the TSH, which allows for analysis.

An analysis is given in the morning, when the hormonal level has not yet been changed by physical exertion and stress, from 8 am to 12 noon. Blood is taken from a vein. You can eat immediately after the procedure.

Knowing how to pass the analysis correctly, you can get the most accurate result, which will give the doctor all the necessary data for competent therapy.

An organ such as the thyroid or endocrine gland performs a number of irreplaceable functions in life cycle not only humans, but also vertebrate chordates.

The thyroid gland produces iodothyronines (iodine-containing), is a "storage" in the body, and also participates in the synthesis hormone T4 (thyroxine or tetraiodothyronine ) and T3 (triiodothyronine ).

When the correct functioning of such an organ as the thyroid gland is disrupted, an inevitable failure occurs in metabolic processes. , occurring every second in our body.

Such an important hormone for the skeletal system as calcitonin , which is involved in the restoration of bones and prevents their destruction, is produced precisely by the thyroid gland. And this is only a small part of what the thyroid gland does for a full and healthy life not only people, but also animals.

Thyroid hormones

Let's pay attention to a number general concepts associated with the work of such an organ as the endocrine gland, before we move on to a direct consideration of thyroid hormones and their role in the process of human life . So, the thyroid gland is perhaps the largest (weight about 20 g) organ of all included in.

It is located on the neck under the thyroid cartilage in front of the trachea and has the shape of a butterfly. The organ consists of lobes connected by the isthmus of the thyroid gland ( lobus sinister, lobus dexter). The size of the thyroid gland, as well as its weight, are purely individual parameters.

According to averaged data, the thyroid gland of an adult can weigh from 12 to 25 g. The volume of the organ in women is approximately 18 ml, and in the male part of the population - up to 25 ml. Moreover, women may experience deviations from the normal size of this organ. This condition is considered a kind of norm and is due to menstrual cycle and other features.

As mentioned earlier, the main "work" of the thyroid gland is the synthesis of two classes of hormones that are indispensable for normal human life. Organ cells produce: triiodothyronine and thyroxine. These biologically active hormonal compounds belong to iodothyronines.

Hormones are involved in the processes of energy and substance metabolism, and also control the maturation and growth of organs and tissues.

Parafollicular C-cells of the organ (part of the diffuse endocrine system) are responsible for the hormone calcitonin - a compound belonging to the class of polypeptides.

This substance is an indispensable participant in the exchange of calcium in the body. Without this hormone, the human skeletal system will not be able to develop and grow properly.

In the case when the thyroid gland produces a small amount of the above hormones, a disease develops. . In this case, there is a failure in the endocrine system and, as a result, in other mechanisms of the body associated with it.

In the normal state, the rate of free thyroxine in women can range from 71.23 to 142.25 nmol / l. For healthy men, the norm of thyroxine is set in the range from 60.77 to 136.89 nmol / l. Such rather large intervals are due not only to gender, but also to the age of the person.

T4 and FT4 are indicators of the effective functioning of the endocrine gland. The highest concentration of thyroxin in the blood falls on the time from 8 am to 12 noon. In addition, it is considered normal if the hormone content is increased in the autumn-winter period.

A decrease in the level of thyroxine in the blood occurs from about 11 pm to 3 am, as well as in the summer season. However, deviations from the established average values ​​can be caused not only by the time of day and sometimes of the year, but also by various diseases. Consider the main reasons that entail changes in the level of thyroxine.

If free T4 is elevated in the analysis, then this indicates the development of such diseases as:

• obesity;
• myeloma disease ;
• , conjugate to ;
• thyroid dysfunction in the postpartum period;
• choriocarcinoma ;
• in acute and subacute stages;
• porphyria ;
• liver disease.

A decrease in the level of thyroxine in indicates the development of diseases such as:

• sheehan syndrome ;
• traumatic brain injury ;
• congenital or acquired;
• inflammatory processes of the hypothalamus or pituitary gland;

In addition, if free thyroxine is lowered, then this may indicate the use of drugs such as: , and . A decrease in FT4 and T4 levels may indicate that the patient is taking antithyroid drugs, anabolics, steroids, diuretics, anticonvulsants, and radiopaque drugs.

Triiodothyronine (hormone T3)

is the second thyroid hormone secreted by the thyroid gland. This hormone is inextricably linked with thyroxine, since it is formed as a result of the breakdown hormone T4. Although T3 is produced in fairly small amounts, researchers believe that it is triiodothyronine that can be considered the main compound of the thyroid gland.

As mentioned earlier, the predecessor T3 is thyroxine (hormone T4) , which contains four molecules of iodine. This hormone is in large numbers produced by the thyroid gland. After one iodine molecule leaves the composition of thyroxine, the hormone T4 is converted into total T3. Thus, a less active compound is replaced by a highly active substance.

Triiodothyronine is involved in many mechanisms of the human body.

In its biological essence, it is this hormone that is the “engine” important processes life support. T3 is responsible for stimulating nervous activity , for the redistribution of energy and brain function.

Normative indicators of total T3 depend on the time of year, as well as on the age of the person.

The following normal levels of triiodothyronine for humans have been established:

• at the age of 1 to 10 years - from 1.79 to 4.08 nmol / l;
• at the age of 10 to 18 years - from 1.23 to 3.23 nmol / l;
• at the age of 18 to 45 years - from 1.06 to 3.14 nmol / l;
• at the age of 45 years and older - from 0.62 to 2.79 nmol / l.

What is this hormone - T3 free?

On hit hormone T3 from the thyroid gland into the blood, it binds to proteins that “transport” it to other organs. Such bound triiodithyronine is referred to as total and is referred to in the assay as TT3. Some small amount of the hormone remains unbound and is called free T3, referred to as FT3.

What it is - free triiodothyronine ? At its core, free T3 is still the same hormone triiodothyronine. It's just that this part of T3 "moves" along circulatory system on its own without the help of proteins. Experts call this hormone the first indicator of the normal functioning of the endocrine gland.

The rate of free triiodothyronine in women, as in men, can vary from 2.62 to 5.77 nmol / l. Such a gap in the normal range of T3 indicators is due to the difference in the methods laboratory research thyroid hormones.

The T3 hormone can be elevated in the autumn-winter period, and triiodothyronine reaches its minimum level in the body, as a rule, in the summer. Almost all hormones depend on the time of year and day, sex and age of a person.

It is worth noting that the norms of free T3 in women can vary not only depending on the type of equipment used for analysis, seasonality and time of day, but also for other reasons. It's all about the structural features of the female body, namely the reproductive system.

Between the ages of 15 and 20 years, values ​​in the range from 1.22 to 3.22 nmol / l are considered normal, and from 30 to 50 years - from 2.6 to 5.7 nmol / l. Gynecologists often refer to free triiodothyronine (FT3) and free thyroxine (FT4) "Female" hormones, since they are responsible for a woman's ability to conceive, endure, and then give birth to healthy offspring.

Therefore, it is so important to maintain normal “female” hormones during pregnancy. If thyroxine and triiodothyronine are out of order, then there is a danger both to the body of the future mother herself and to the health of her baby.

Pregnant women are periodically hormonal blood tests (screening) in order to early stages identify problems in the endocrine system. In addition, if there is a real need to correct the hormonal background, resorting to the help of medications.

Total and free triiodothyronine are elevated with:

• obesity ;
• thyroid dysfunction in the postpartum period;
• porphyria;
• multiple myeloma;
• hyperestrogenism;
• glomerulonephritis;
• thyroiditis (adolescent and acute);
• chronic liver diseases;
• choriocarcinoma;
• toxic goiter.

In addition, an increased content of triiodothyronine in the blood may indicate that the patient is taking analogues of thyroid hormones of synthetic origin, as well as drugs such as , and . Also, an increase in T3 is characteristic of the state after the conduction.

Total and free T3 can be lowered with:

• some mental pathologies;
• low protein;
• hypothyroidism;
• malfunction of the adrenal glands.

Besides, low level triiodothyronine may be a consequence of the use in the treatment antithyroid drugs, for example, Propylthiouracil and , steroids, beta-blockers such as .

As a rule, the level of T3 below the normative indicators is observed in patients taking anabolics and statins , for example, and , as well as such non-steroidal anti-inflammatory drugs (NSAIDs) , how or and radiopaque compounds.

Often, the indicators of many hormones deviate from the norm during the recovery period of the human body after suffering ailments. It is important to know that a decrease in the level of T3 is always the result of a change in the normative indicators of the hormone T4.

These two are biologically active compounds are closely interconnected. And although thyroxine is considered an inactive hormone, it is also indispensable for humans, like triiodothyronine. When the body feels a lack of T3, a defense mechanism called peripheral conversion . As a result, thyroxine, which the thyroid gland produces in excess, is processed into highly active triiodothyronine.

The body is trying, thus, to correct the situation on its own and adjust its hormonal background. However, this doesn't always work. If the free T3 hormone is elevated, what should I do? First, there is always the possibility of error in research. Also, an incorrect result of the analysis may be the result of non-compliance with simple rules for preparing for the study of thyroid hormones.

Therefore, it is worthwhile to correctly approach the diagnosis and retake the analysis for hormones. Secondly, it is advisable to seek advice from an endocrinologist as soon as possible. The specialist will be able to explain what specifically caused the abnormal levels of thyroid hormones. If necessary, the specialist will give recommendations for treatment or further examination.

Thyroid Stimulating Hormone (TSH, TSH)

Thyroid-stimulating hormone (thyrotropin, thyrotropin) - This is a hormone of the pituitary gland, or rather its anterior lobe. Although the endocrine gland itself does not secrete this glycoprotein hormone, TSH plays an important role in its smooth functioning. Thyrotropin acts on thyroid receptors, thus stimulating the activation and production of thyroxine.

As a result of the effect of TSH on thyroid cells, they begin to consume more iodine, which leads to the biosynthesis of hormones such as T3 and T4, which are indispensable for the human body.

In addition, thyrotropin affects the number and size of thyroid cells, and also stimulates the production of phospholipids, nucleic acids and proteins.

All vital systems of the body must work like a clock so that a person can live a full life. So in the case of thyroid hormones, everything is also well arranged.

There is an inverse relationship between thyroxin and thyrotropin. If the thyroid gland increases the production of T4, then the level of thyrotropin in the blood automatically decreases and vice versa.

Blood test for TSH

Analysis for TSH - what is this study and why is it carried out? Most often, people get to the endocrinologist for the first time in the direction prescribed by the local therapist, who notices primary symptoms thyroid diseases. A narrow specialist, which is an endocrinologist, usually prescribes an ultrasound of the thyroid gland and a blood test for TSH , T3 , T4 , AT-TG and AT-TPO .

This is the so-called minimum of research, which allows the doctor to draw a conclusion about the state of the patient's endocrine gland. And although, in its biological essence, thyrotropin does not belong to the hormones produced by the thyroid gland, deciphering the analysis for TSH is considered a very important step in detecting pathologies associated with the endocrine system of the body.

Many people, when they first hear a list of unfamiliar names of hormones or their abbreviations, ask in bewilderment: “ What are these analyses?". Many even begin to worry and worry in vain about the very procedure of donating blood for research.

In fact, there is nothing to worry about here, you just need to learn how to properly donate biological material (in this case, blood) for further laboratory research. An endocrinologist or a specialist in a medical laboratory can tell you in detail how to take an analysis for TSH.

Here are a few general rules, which will help prepare for any kind of blood tests, including endocrine hormones:

• it is recommended to reduce or completely eliminate physical activity for some time before the study;
• biological material (i.e. blood from a vein) should be taken only on an empty stomach;
• the day before the study do not drink alcohol, as well as heavy fatty or overly spicy and spicy foods;
• before the analysis, you can drink water, preferably ordinary;
• it is recommended (if possible) a few weeks before the analysis to stop taking any medical preparations;
• if the drugs are vital, then it is worth notifying the specialist of the research laboratory about this so that the analysis can be corrected for the presence of drugs in the blood.

The norm of thyroid-stimulating hormone

A feature of the hormone thyrotropin is that its level in blood plasma depends on seasonality and time of day. In addition, for different ages established individual norms of TSH hormone. The most significant concentration of TSH in the blood is observed at about 2-3 am, and the smallest amount of the hormone can be recorded at about 5-6 pm.

Such daily fluctuations in secretion are inherent in many types of hormones, including thyroid hormones. It is interesting that in violation of the sleep regime, an inevitable failure in the synthesis of thyrotropin occurs in the human body, which entails a number of serious ailments.

The table below shows the norm of the TSH hormone for people of different ages.

Normal TSH in women

As can be seen from the table above, the normal TSH for men and women is considered to be the range of values ​​from 0.47 to 4.15 mU/L. As you can see, both gender categories are combined into one age group "Adults". These standards, although general, are still reliable.

However, due to the peculiarities in the structure of the female body (mainly the reproductive system), many experts tend to share such concepts as the TSH norm for women and men. So, what level of thyroid-stimulating hormone (TSH) in women is the norm, and which one signals a dangerous deviation?

As mentioned earlier, an analysis for such "female" hormones of the endocrine gland , how T3 and T4, mandatory for all pregnant women. That's just the same big role for the mother and the unborn child is played by thyrotropin. Therefore, it is very important to maintain normal TSH hormone in women during pregnancy.

During the period of preparation for the birth of a child, the body is rebuilt and works in a new way, absolutely different from its usual mode, in order to provide for all the needs of a baby growing in the womb. Therefore, for women in position, their own “normal” indicators (adjusted for their condition) of certain analyzes of biological fluids (urine, blood, and so on) are established.

As is the case with the hormones T3 and T4 free, the rate of TSH in the blood of women in position differs from the general indicators established for healthy adults. AT I trimester the level of thyrotropin decreases, which is due to the production of more than usual amounts of thyroxine and triiodothyronine.

From 6 to 13 weeks, TSH should be in the normal range for this period from 0.1 to 2 mIU / l. In II trimester (from 14 to 27 weeks) - from 0.2 to 3 mIU / l, and in III (from 28 to 41 weeks) - 0.3-3 mIU / l. At multiple pregnancy often there is a complete suppression of the production of the hormone thyrotropin.

This condition is considered normal and does not require any correction. Not only during pregnancy should be given Special attention hormonal background of the female body. For women after 50, the norm of thyroid-stimulating hormone, like other "female" hormones, is set taking into account the changes that have occurred in their body ( , ).

If the thyroid-stimulating hormone is above normal, then this most likely indicates diseases such as:

• pituitary adenoma ;
• preeclampsia ;
• adrenal insufficiency;
• Hashimoto's thyroiditis ;
• thyroid hypofunction.

In addition, if, according to the results of the analysis, TSH is above normal, then this means that the patient is taking anticonvulsant or antiemetic drugs, beta-blockers, neuroleptics, as well as radiopaque agents .

, and may also affect thyroid-stimulating hormone levels. Deviation from TSH standards can be the result of excessive physical exertion, therefore, before donating blood for thyrotropin, you need to give up sports for a while.

If a TSH lowered, this indicates such ailments as:

• damage to the pituitary gland;
• hyperthyroidism during pregnancy;
• stress;
• toxic goiter;
• pituitary necrosisa in the postpartum period.

Thyrotropin levels can also be reduced by medications such as: beta-agonists, anabolics, cytostatics, glucocorticosteroids, as well as , and . In addition, with prolonged fasting, for example, if a person followed a strict diet for weight loss, a blood test will show a deviation from the norm of TSH.

When the body is healthy, it is normal and hormones T3, T4, TSH . If there is a big difference between the indicators of the patient's analyzes and the standard values, then this indicates serious problems. With a normal hormonal background, slight deviations from the average values ​​of thyroxine, thyrotropin and triiodothyronine are allowed.

This is connected, for example, with the time of year. True, if hormones T3 and T4 normal, and TSH increased or vice versa, then this is the first signal about hypothyroidism . This disease at the initial stage develops asymptomatically and if left untreated, it leads to serious complications (adults develop myxedema , and in children cretinism ).

- This is a condition caused by a lack of endocrine hormones in the human body, usually for a long period. When observed elevated levelT3 and T4 in the blood, this indicates the development hyperthyroidism, those. a disease in which the endocrine gland intensively produces "extra" hormones for the body.

What it is thyroglobulin ? In its biological essence, it is a protein that is found in the follicles of the thyroid gland. The protein thyroglobulin is the substrate on the basis of which thyroid hormones are produced. TG, passing through the thyroid gland, breaks down into atoms iodine and molecules tyrosine , eventually produced thyroxine .

The thyroglobulin protein has a large molecular weight and can provide the production of thyroid hormones important for the human body for two weeks.

Such a blood test parameter as TG is important to investigate if there is a suspicion of cancer in a patient. He is called tumor marker or tumor marker .

Due to mutations in thyroid follicular cells, there is an increase in the production of TG protein. As a result, it develops follicular or papillary cancer . It's believed that surgical intervention- this is effective method fight these diseases. After removal of the thyroid gland, the thyroglobulin norm for the patient is zero for life.

This minimum low concentration of protein must be constantly maintained in the body throughout life. For maintenance postoperative therapy, patients are prescribed this dosage or to completely block the production of the pituitary hormone TSH.

For an adult without significant health problems, the following thyroglobulin norm has been established - less than 60.08 ng / ml. As a rule, if thyroglobulin is elevated, it means that malignant tumor thyroid glands . However, other factors can affect the content of this protein in blood plasma.

If thyroglobulin is elevated, then the reasons may be:

• autoimmune inflammatory processes;
• destruction of thyroid cells due to the development papillary or follicular cancer ;
• purulent inflammation;
• therapy using radioactive iodine ;
• postoperative complications.

It is important to remember that during pregnancy in a blood test in women, the thyroglobulin norm differs from the above indicated values. First of all, this is due to the changes that have occurred in the body of the expectant mother. Therefore, pregnant women should not panic if the level of this protein is elevated. Also, a high TG can be observed in newborns.

The level of thyroglobulin decreases with:

• thyrotoxicosis ;

Thyroxine-binding globulin (TSG)

thyroxine-binding globulin is the main carrier iodothyronines in the blood of the human body. TSH is produced in the liver, but plays a major role in ensuring the normal functioning of the endocrine gland.

The reasons for the deviation of the level of thyroxin-binding globulin from the normative indicators can be:

• with an increased amount of TSH - hypothyroidism, viral hepatitis, reception Methadone, oral contraceptives, as well as porphyria;
• with a reduced amount of TSH - ovarian hypofunction, stress, somatic disorders, thyrotoxicosis, protein starvation, reception anabolics, glucocorticosteroids, beta-blockers, as well as transferred surgeries. .

Thyroid Hormone Absorption Test

This test is carried out in order to study changes in proteins that bind free hormones T3 (triiodothyronine) and T4 (thyroxine) . Based on the results of the study, the doctor can diagnose the patient hypothyroidism or hyperthyroidism . In a thyroid hormone uptake test, a person is given a drug based on radioactive iodine .

This technique allows you to fix the path of a microelement in the human body. In this case, the path of thyroid hormones. If low iodine uptake is detected, the diagnosis is made hypothyroidism , and the high thyrotoxicosis .

Antibodies to thyroperoxidase (AT to TPO) - what is it?

Having received a transcript of the hormonal analysis of the thyroid gland, many are wondering what it is - hormone AT-TPO ? First of all, it is important to understand that thyroperoxidase - this is an auxiliary, participating in the process of synthesis of such hormones , how T3 and T4 thyroid gland.

Biologically, antibodies to thyroid peroxidase – this is autoantibodies, those. antibodies that interact with the body's antigens. Such an indicator as AT-TPO, important for the analysis of the state of human health.

Antibodies to thyroperoxidase appear in the blood plasma if thyroid cells are perceived immune system human as foreign substances.

If the level of antibodies to thyroid peroxidase is normal, then this indicates that the production of thyroid hormones is going according to plan.

An enzyme such as thyroperoxidase , participates in the process of iodine production.

In addition to the main indicators in the hormonal analysis, it is no coincidence that there is information about antibodies to thyroperoxidase, thyroglobulin, and also to TSH receptors. Since a deviation from the norms above the indicated indicators is a signal for the development of certain pathologies of the thyroid gland in a patient, as well as autoimmune diseases.

The level of AT-TPO increases:

• at ;
• at ;
• at ;
• at Hashimoto's thyroiditis ;
• at ;
• at vasculitis .

With an increase in antibodies to thyroperoxidase, the following symptoms appear:

• goiter (enlarged thyroid gland);
• brittle hair;
• cardiopalmus;
• puffiness;
• increased sweating;
• hearing loss;
• change in voice.

The reasons for the increase in the level of antibodies to TPO may be some chronic diseases, hereditary factors, viral infections or toxin poisoning. It is important to note that deviations from the normal values ​​of AT-TPO during pregnancy indicate the possibility of developing hyperthyroidism in a child.

In addition, an increase in the level of antibodies to thyroperoxidase is a risk factor. Therefore, pregnant women are simply obliged to donate blood regularly for hormones.

AT-TPO norm in women

As mentioned earlier, such an indicator as AT-TPO plays a really important role for pregnant women. However, control over the level of antibodies to thyroid peroxidase should be carried out not only by expectant mothers, but also by all other representatives of the fair sex, regardless of age.

Since it is in the female part of the population this indicator often deviate from the norm. The consequences of an increase in the level of antibodies to TPO can severely affect human health and disable the musculoskeletal system, nervous and cardiovascular system. In the female body, the reproductive system is the first to suffer, which leads to infertility or the risk of spontaneous miscarriage.

It is considered normal if the values AT to TPO increased within 20 U / ml. If the indicators deviate by 25 U / ml or more, the patient urgently needs appropriate treatment. The above table of norms of antibodies to thyroperoxidase provides information for people of different ages, without breakdown by sex.

It is noteworthy that in women the rate of antibodies to thyroperoxidase depends not only on age. For example, during pregnancy, and already in the first trimester, the values ATPO rises. This is due to changes that have affected not only the endocrine and reproductive system, but the entire female body in general, which is preparing for childbearing and for future births.

If the level hormone ATPO increased, what to do in such a situation? Firstly, do not panic, statistics say that every tenth woman and twentieth man has antibodies to thyroperoxidase in the analysis. In itself, the presence of antibodies is not bad news; it is another matter if the level of ATPO is significantly increased in comparison with the established standards.

Secondly, you should immediately seek a second consultation with an endocrinologist, who will definitely prescribe a number of additional laboratory tests and other procedures to clarify the final diagnosis. As a rule, in addition to a blood test for the main hormones and indicators characterizing the work of this vital organ, you will need to undergo Ultrasound of the endocrine gland.

Of course, it is better not to bring your body to the disease and regularly undergo an examination by an endocrinologist. Especially in our time, when problems with the endocrine system are found everywhere due to poor ecology and a fast rhythm. modern life. Prevention is considered the best defense against many health problems.

Antibodies to thyroglobulin (AT-TG)

What it is AT-TG, And what is the effect of this indicator? Anti-thyroglobulin antibodies are called the main parameter that is used to test the thyroid gland for the presence of serious autoimmune diseases . By its biological nature thyroglobulin - is nothing but glycoprotein , which is part of the follicles of the thyroid gland.

In the synthesis of thyroid hormones, this biologically active compound plays a role Propeptide (i.e. protein , contained in the thyroid gland). Until now, science does not know for certain the reasons why thyroglobulin becomes an "enemy" for the body and goes into the category autoantigens .

Sensing danger, the human body launches protective mechanisms, starting the active production of antibodies that combine with thyroglobulin and mimic hormonal activity. In simple words, block thyroglobulin and "deceive" the thyroid gland. As a result, the gland secretes more hormones, thereby disrupting the metabolism and the functioning of the cardiovascular system.

When antibodies to TSH are elevated, this means that the following diseases can be detected in the patient in the future:

• thyroiditis in chronic or subacute stages;
• Hashimoto's thyroiditis ;
• myxedema idiopathic ;
• Graves' disease ;
• pernicious anemia ;
• hypothyroidism ;
• non-medullary, papillary, follicular thyroid carcinomas ;
• goiter .

Hormone Thyrocalcitonin

Or thyrocalcitonin is a hormone that is secreted by the parafollicular cells of the thyroid gland of humans and other mammals. Thyrocalcitonin is important in calcium-phosphorus metabolism and belongs to parathyroid hormone antagonists (abbreviated PTH).

Parathyroid hormone is produced by the parathyroid gland of the thyroid gland. as a PTH antagonist, it weakens the production of parathyroid hormone, which helps to avoid diseases such as hyperparathyroidism .

It occurs when parathyroid hormone is elevated. In addition, an increase in the level of PTH in the blood leads to hyperplasia , cancer of the parathyroid or parathyroid glands.

also important for balance. osteoblasts and osteoclasts .

It reduces the level of phosphorus and calcium in the blood, and also stimulates the process of reproduction and functional activity. osteoblasts .

And, conversely, in the course of resorption (destruction, degradation) of bones, it suppresses similar processes in relation to osteoclasts .

is a tumor marker, i.e. compound that indicates whether the patient has thyroid cancer .

If the level of calcitonin in the blood exceeds 100 pictograms per milliliter, then the doctor is likely to diagnose medullary thyroid cancer . Therefore, an analysis for calcitonin is indicated for people if the endocrinologist suspects the presence of malignant tumors.

Also calcitonin is an indicator of the effectiveness of cancer treatment. An analysis for this hormone should be constantly taken by people with a removed thyroid gland, so that the doctor can diagnose a relapse of the disease in time, as evidenced by a sharp jump in the level of calcitonin in the blood.

• liver cancer;
• liver or kidney failure;
• stomach cancer;
• thyroiditis;
• pernicious anemia;
• breast cancer.

Norma Calcitonina

It is important to note that for studies of the level of calcitonin in the blood, it is most often used linked immunosorbent assay , at which the level of the hormone is determined using a labeled reagent. This compound reacts exclusively to thyrocalcitonin and changes its color when it encounters the hormone.

Since different reagents can be used in research laboratories, the standards for thyrocalcitonin are set as a numerical range of normal values. In addition, it is important to note that the norm of the hormone calcitonin in women differs from the indicators established for men.

When using the enzyme immunoassay method, the norm of calcitonin:

• for men it is 0.68-32.26 mg / ml;
• for women it is 0.07-12.97 pg / ml;
• for newborns is set at 70-150 pg / ml;
• for children from one year and older - up to 70 pg / ml.

When a person is faced with a number of ailments, he is faced with the question of how to check the thyroid gland and what tests need to be taken for this.

An endocrinologist deals with issues related to the endocrine system of the body, who prescribes a series of laboratory tests to the patient for subsequent analysis of the thyroid gland and making a correct diagnosis in case of deviations in the functioning of this organ.

Thyroid analysis - This is part of a general hormonal study, which is prescribed to check the patient's hormonal levels.

Indications for the appointment of an analysis for hormones in men and women are the following ailments:

• atrial fibrillation;
• failure in the menstrual cycle;
• sudden weight loss;
• a sharp increase in body weight;
• miscarriage;
• pituitary adenoma;
• infertility;
• diseases of the mammary glands;
• excessive hairiness;
• lack of sexual desire;
• obesity;
• sexual dysfunction;
• baldness.

Hormonal studies are prescribed to a child if the pediatrician has diagnosed him with a delay in psychological and mental development, obesity, advance or lag in growth, sexual development, and increased hairiness. The main task of this blood test can be considered the diagnosis hormonal diseases and control over their treatment.

For example, after removal of the entire gland or its share, hormonal studies (hormone test) are carried out regularly to maintain medical methods the amount of thyroglobulin in the blood necessary for the normal life of the patient. Of particular importance is the analysis of hormones in women. The thing is that thyroid hormones are closely related to reproductive function.

Decoding tests for thyroid hormones can answer many questions, for example, can a woman conceive and bear a healthy child. It is important for representatives of the beautiful to know as much as possible about the state of their thyroid gland, since this body is responsible for the production of the so-called "female" hormones T3 and T4.

For women of any age, it is advisable to do an ultrasound of the thyroid gland at least once a calendar year and undergo hormonal studies.

Such procedures become especially relevant after the age of 50, when, as a rule, most of the fair sex has menopause.

Deciphering the results of ultrasound of the thyroid gland, coupled with hormonal studies, gives the specialist the opportunity to analyze the state of the endocrine system and, if necessary, prescribe the appropriate treatment.

About how to take a hormone test for a woman, either a gynecologist or an endocrinologist can explain in detail. However, preparation for this analysis is not much different from any other preparation for laboratory studies of biological fluids.

How to prepare for donating blood for hormones?

Let's consider the main questions and make a universal reminder on how to take such tests correctly. Often people have a question about where they take blood for analysis? Blood sampling for this study carried out from a vein. Of course, this is not a particularly pleasant procedure, but it is in the venous blood that a sufficient amount of hormonal material is contained to conduct such a study.

Remember, you can not take a hormonal analysis without prior preparation. Otherwise, you will simply waste your time and money, since the results of such a study will not only be distorted, but also unreliable.

Another common question - do you give blood for hormones on an empty stomach or not? In most cases, blood for research (including thyroid hormones) is donated on an empty stomach.

This is a universal rule for almost all laboratory studies. Since food contains a huge amount of various biologically active ingredients(fats, proteins, carbohydrates, glucose , acids and many other substances), all of which can affect the final result of the analysis.

In addition, some medications can distort hormonal studies. Therefore, about a month before the analysis, it is necessary to stop taking hormone-containing drugs. You will also have to do with medicines containing iodine , oral contraceptives, tranquilizers and aspirin.

Blood for analysis for hormones is taken exclusively in the morning, from about 8 to 10 in the morning. This rule is due to the fact that the concentration of certain hormones in the blood depends not only on the patient's gender and age, but also on the time of day and year.

The psycho-emotional mood of the patient before hormonal studies is also considered important. If the patient is nervous, afraid or worried, then the results of his analysis will be inaccurate. Since nervous tension will provoke an increased production of hormones that should help the human body cope with stress. In general, you should not worry and worry before donating blood.

A week before blood tests for hormones, it is recommended to stop drinking alcohol. This also applies to smoking. Although there is a catch here. If a smoker quits smoking even for a couple of days, not to mention a whole week, then his body will experience tremendous stress. Which will eventually lead to a psycho-emotional imbalance, and such a state is absolutely not acceptable before a hormonal study.

Therefore, experts ask to smoke less, and on the day before the direct delivery of the biomaterial, it is worth a little patience. Physical exercise can distort the final results of the tests, so it is advisable to refrain from playing sports for some time before the study.

Where to take and how much does a hormone test cost?

Hormonal studies refer to specific blood tests that are carried out in specialized laboratories using a variety of auxiliary reagents. Therefore, in state clinics, such studies are carried out extremely rarely, especially for free. If the result of the analysis for hormones needs to be obtained as soon as possible, then it is best to contact private laboratories, for example, in Invitro.

It is convenient that it is not at all necessary to come personally for the results of the study, they can be sent to you online mode on e-mail. The cost of such a study will depend on your location, as well as on the number of indicators studied. As a rule, each hormone has its own separate price.

The price of an analysis for hormones in women, as in men, as well as children, is formed based on the amount of hormones being studied, as well as other significant indicators(globulin, antibodies, etc.). The most financially beneficial is a comprehensive analysis.

This study includes all the main indicators that are used to analyze the hormonal balance of the human body. The hormonal analysis includes:

• analysis for endocrine gland hormones (T3, T4, AT-TG, AT-TPO, TG, TCG );
• analysis pituitary hormones (TSH, luteinizing hormone, adrenocorticotropic hormone or ACTH, follicle stimulating hormone, prolactin );
• analysis sex hormones (estrogen, testosterone );
• analysis adrenal hormones (aldosterone, DHEAS, cortisol ).

The T3 hormone is a thyroid hormone and is the most active of the two main hormones. You can meet its other name - triiodothyronine. The presence of the number three in the definition of a hormone is explained by the fact that each of its molecules contains just such an amount of iodine.

T3 is formed as a result of the breakdown of another hormone - T4, when one atom of iodine is split off from it. The process that occurs after the splitting off of an atom can be compared to the process of removing the pins from a grenade. The transformed, previously inactive T4, having transformed into triioditrin, becomes very active.

Its purpose is to control energy metabolic processes occurring in the human body. The hormone influences the breakdown of energy and sends it to where it is needed. Once in the bloodstream into the cells of the child's brain, the hormone contributes to its rapid development. Thanks to the work of triiodothyronine in an adult, there is an increase in nerve conduction.

Triiodothyronine is important for the heart system and bone tissue, as it contributes to the activation of metabolism in them. General nervous excitability increases under the influence of triiodothyronine.

Hormone T3 free and general - what is it?

A certain amount of triiodothyronine is able to be produced by gland cells in an already “ready” state, that is, with 3 iodine atoms. Once in the bloodstream, it is connected with the molecules of transporter proteins. Through the vessels, the hormone is transferred to the tissues that need it. But in a small amount, triiodothyronine remains in the blood, in an unbound form with protein molecules. This triiodothyronine is called "free T3 hormone".

The hormone that remained free in conjunction with that bound to proteins is defined as total T3 hormone. It is its amount that is often indicative, with questionable results of tests for free hormone, which are carried out to determine work disorders in humans.

T3 hormone analysis

When determining the pathological conditions of the thyroid gland, the endocrinologist without fail sends the patient to take tests for three hormones - T4, TSH, T3. Research on the last type of hormone is extremely important, as it allows you to minimize the diagnostic error.

For example, with nodular toxic goiter, very often independently working nodes are engaged in the reproduction of the hormone T3. Also, its amount increases with diffuse toxic goiter, Graves' disease and Graves' disease. If the analysis gives a result that shows a significant increase in triiodothyronine, then doctors talk about T3 toxicosis. This condition is difficult to treat with medication and manifests itself with more vivid symptoms than those that are found with an increase in the amount of the hormone T4.

The norm of the hormone T3

Depending on what equipment is used to conduct a study on hormones, the norm indicators will vary. Each specific laboratory makes a choice in favor of a particular apparatus and a set of reagents. Therefore, it is impossible to determine the concept of "triiodothyronine norm". Its amount will be considered normal if the results obtained fall within the reference limits indicated on a specific form of a particular laboratory. The form is formed on a computer, where the amount of the hormone is accurately determined and the limits of the norm are indicated.

Elevated T3 hormone

Many pathological conditions thyroid cause an increase in triiodothyronine. At the same time, a person cannot help but notice that something is happening to his body. Due to the fact that T3 is an extremely active hormone, its increase in the blood causes a number of very pronounced symptoms:

The patient becomes excessively irritable, nervous, quickly becomes enraged and agitated. Against the background of this patient, fatigue constantly haunts. Physicians sometimes refer to this set of symptoms as irritable weakness;

Tremor of the fingers upper limbs- Another common sign of an increase in triiodothyronine;

The patient's pulse quickens, symptoms are observed, failures occur in heart rate. Extrasystole is a symptom of an increase in the hormone. This condition is characterized by an increase in the number of heartbeats with a long period of rest. A person feels these disorders and often complains to the doctor about "interruptions" in the work of the heart;

Often there is a loss of body weight.

Conducting an analysis to detect the level of triiodothyronine is considered quite complicated procedure. Mistakes often occur in laboratories. You can think about them yourself in the case when an additional test was carried out to detect the level of other thyroid hormones - TSH and T4. If the results obtained show that TSH is normal, and T3 is elevated, then most likely an error has occurred. The unreliability of the analysis can also be judged on the basis of an increase in T3 and TSH, but normal T4 values ​​\u200b\u200bat the same time. If such results were obtained, then it makes sense to double-check the data. This is due to the fact that with an increase in T3, the level of TSH decreases, and T4 increases.

If the tests were carried out qualitatively and the results unequivocally indicate an increase in triiodothyronine, it is necessary to consult an endocrinologist.

If the T3 hormone is low

A decrease in the level of triiodothyronine is observed when the production of all hormones produced by the thyroid gland is disrupted. This condition occurs when serious illnesses:

There is such a disease - Hashimoto's thyroiditis, when a person's own immunity begins to destroy some of the cells of the thyroid gland. These cells cannot be repaired and, in most cases, permanently cease to function and produce hormones.

Hypothyroidism. This condition often develops while taking certain drugs used to treat diffuse and nodular toxic goiter. As potentially dangerous agents, thyreostatics such as Propicil, Tyrozol, Mercazolil can be noted.

Triiodothyronine levels may be lowered when surgery has been performed to remove either the entire thyroid gland or a specific part of it.

The level of T3 decreases against the background of a person undergoing treatment with radioactive iodine. Such therapy is carried out when it is necessary to save the patient from diffuse toxic goiter.

A drop in hormone production is observed when taking drugs containing an impressive amount of iodine. Among these, cordarone, amiodarone and others can be noted.

It is worth knowing that hormones do not decrease in a chaotic manner. T4 levels are always the first to fall and only after that does it decrease. normal value triiodothyronine. This state is due to the activity of the body. When the T3 hormone falls, he tries to insure himself and, as it were, transfers “cash into a freely convertible currency”, because triiodothyronine is almost 10 times more active than T4. Doctors call this activity of the body an increase in the peripheral conversion of T4 to triiodothyronine. Thanks to this process, the consequences of hypothyroidism are not as acute as they could be. Knowing this, you can independently suspect a laboratory error. If the analysis showed that the level of triiodothyronine is reduced (and it does not matter which hormone it is - total or free), but at the same time TSH and T4 remain within the normal range, then you should double-check the data obtained and donate blood for hormones again.

After all, a deficiency of thyroid hormones is a serious pathology. A disease in which the function of the thyroid gland decreases is fraught with the development of such processes as: drowsiness, weight gain, deterioration of thought processes and speech, disruptions in the menstrual cycle in women. If the disease is severe, then childhood cretinism is often observed, and adults suffer from myxedema. However, peripheral hormone conversion avoids these manifestations if treatment was started in a timely manner.

Education: Diploma of the Russian State Medical University N. I. Pirogov, specialty "Medicine" (2004). Residency at the Moscow State University of Medicine and Dentistry, diploma in Endocrinology (2006).

A thyroid hormone test is a study of the level of thyroid hormones (thyroxine and triiodothyronine) and the associated thyroid-stimulating hormone. The examination is prescribed by doctors of various specialties and today is the most popular of all hormone tests.

Why are these tests ordered?

Analysis of thyroid hormones is relevant in practice:

The function of the thyroid gland affects the functioning of the cardiovascular, nervous, digestive, hematopoietic, and reproductive systems.

Thyrotoxicosis and hypothyroidism can mimic clinical picture other diseases. For example, the "masks" of low thyroid function are depression, obesity, chronic constipation, Iron-deficiency anemia, dementia, infertility, menstrual disorders, hearing loss, tunnel syndromes and other conditions.

Thyrotoxicosis should be excluded if tachycardia, atrial fibrillation, arterial hypertension, insomnia, panic attacks and some other pathologies.

Indications for the analysis of thyroid hormones:

1. the presence of signs of thyrotoxicosis (tachycardia, extrasystole, weight loss, nervousness, tremor, etc.);
2. the presence of signs of hypothyroidism (bradycardia, weight gain, dry skin, slow speech, memory loss, etc.);
3. diffuse enlargement of the thyroid gland on palpation and according to ultrasound;
4. nodular formations of the thyroid tissue according to the examination and additional studies;
5. infertility;
6. menstrual irregularities;
7. miscarriage;
8. a sharp change in weight against the background of a normal diet and physical activity;
9. heart rhythm disturbances;
10. dyslipidemia (increased total cholesterol and atherogenic index);
11. anemia;
12. impotence and decreased libido;
13. galactorrhea;
14. delayed mental and physical development of the child;
15. control conservative treatment with diseases of the thyroid gland;
16. control in postoperative period(subtotal resection, resection of the lobe, extirpation of the thyroid gland) and after radioisotope treatment.

In addition, the analysis for thyroid-stimulating hormone (TSH) is included in neonatal screening, that is, it is mandatory for all newborns in Russia. This study allows you to detect congenital hypothyroidism in time and start the necessary treatment.

How to properly prepare?

Thyroid hormones are influenced by many factors. In order to avoid mistakes in the study, it is important to properly prepare.

It is advisable to take all tests for thyroid hormones on an empty stomach. This means that at least 8 and no more than 12 hours should pass from the last meal. At this time, you can not drink sweet drinks, juice, coffee, tea, use chewing gum.

On the evening before the study, it is necessary to exclude the intake of alcoholic beverages.

Blood must be donated before 10 am.

Hormonal pills (L-thyroxine and others) can be taken only after taking blood for thyroid hormones.

Smoking must be stopped more than 60 minutes before blood sampling.

Before taking blood, the patient should rest (breathe) slightly for 10-15 minutes.

In the morning before the analysis, you can not undergo an X-ray examination, ECG, ultrasound or physiotherapy procedures.

Studies with X-ray contrast should be carried out no later than 2–4 days before blood sampling for analysis.

Deciphering the results of the analysis for thyroid hormones - the norms of the indicators in the table

Different laboratories may use different methods, units of measurement and reagents, and standards often differ accordingly.

Hypothyroidism and hyperthyroidism of the thyroid gland - abnormalities in the analyzes

Hypothyroidism is a decrease in thyroid function. In this condition, insufficient thyroid hormones are produced. Accordingly, in the analyzes, a decrease in free thyroxine (T4) and free triiodothyronine (T3) is observed. Quite often, the ratio of T3 and T4 increases (normally< 0,28).

Increased TSH- This is a normal reaction of the pituitary gland in primary hypothyroidism caused by a thyroid disease. Thyroid-stimulating hormone stimulates the work of thyrocytes. This indicator changes even with minor violations. Therefore, TSH rises in primary hypothyroidism even before T4 and T3 fall. These initial changes are interpreted as subclinical hypothyroidism.

Combination of low TSH and low thyroid hormones indicates secondary hypothyroidism. That is, about the low function of thyrocytes due to damage to the pituitary gland.

Decreased T3 and T4 without an increase in thyroid-stimulating hormone, it is evaluated as a laboratory effect and is interpreted as euthyroidism.

In hypothyroidism, markers of the autoimmune process, AT-TPO and AT-TG, are often detected. A high antibody titer helps to establish the cause of a decrease in thyroid function - autoimmune thyroiditis.

Treatment of hypothyroidism hormone replacement drugs (L-thyroxine and triiodothyronine) is controlled by the level of TSH. The target value for patients after surgery for cancer is below 1 µIU / ml, for pregnant women and women planning to conceive - up to 2.5 µIU / ml, for patients with myocardial ischemia - up to 10 µIU / ml, for the rest - 1-2, 5 µIU/ml.

Hyperthyroidism- a state of excessive functional activity of the thyroid gland. In practice, the term thyrotoxicosis is often used.

With hyperthyroidism, the levels of T3 and T4 in the blood increase. There may be an isolated increase in only one of the hormones. T3 thyrotoxicosis is more common in elderly patients and is clinically manifested primarily by damage to the cardiovascular system.

Primary thyrotoxicosis manifested by a decrease in TSH. Thyroid-stimulating hormone can be suppressed to almost zero values. If this indicator is reduced, and T3 and T4 are within the normal range, then we can talk about subclinical thyrotoxicosis.

If high concentrations of thyroid hormones are combined with high TSH, the doctor may suspect secondary hyperthyroidism. This condition most often occurs with hormonally active pituitary adenoma.

Increased T3 and T4 without a decrease in thyroid-stimulating hormone evaluated as a laboratory effect and treated as euthyroidism.

In thyrotoxicosis, high antibody titers can be detected. In this case, the cause of the disease is most likely Graves' disease (diffuse toxic goiter).

Blood test for thyroid hormones during pregnancy

Pregnancy affects thyroid function and makes laboratory determination of thyroid hormones difficult.

The first trimester is characterized by a state of physiological thyrotoxicosis. TSH may be slightly below normal, and T3 and T4 may be elevated. These laboratory abnormalities occur in 20–25% of all women.

Throughout pregnancy, thyroid-stimulating hormone may remain suppressed or is at the lower limit of normal. Thyroid hormones (T3 and T4) may also be in the upper normal range or even slightly higher in a normal pregnancy.

Usually, a woman does not have any complaints or symptoms of impaired thyroid function. The condition does not require treatment.

With persistent, pronounced thyrotoxicosis, according to tests, signs of autoimmune damage to the thyroid gland and clinical manifestations, medical or surgical treatment can be prescribed.

Much more dangerous during pregnancy is low thyroid function. Hypothyroidism is diagnosed when TSH values ​​are above 2.5 µIU/ml in the first trimester and above 3 µIU/ml in the second and third.

The detection of elevated TSH during pregnancy requires the immediate administration of hormonal therapy (L-thyroxine). Hypothyroidism can lead to fetal malformations and abortion.

Where to get tested for thyroid hormones - prices in laboratories in Moscow and St. Petersburg

In state medical institutions in Moscow, St. Petersburg and other cities of Russia, it is possible to determine the hormones TSH, T3, T4, thyroglobulin and antibodies. However, unfortunately, in most cases, funding for laboratory diagnostics is insufficient.

Tests for thyroid hormones can be taken at any paid laboratory. These popular examinations are performed quickly and with high accuracy.

In Moscow, the most specialized institution is the laboratory of the Endocrinological Research Center. The cost of TSH analysis in the Center is 460 rubles, T3 - 550 rubles, T4 - 460 rubles, AT-TPO and AT-TG 490 and 450 rubles, respectively.

There are dozens of private medical centers in St. Petersburg that provide blood sampling services for analysis. You can donate TSH, T4, T3, thyroglobulin and antibodies at the clinics of the North-West Endocrinology Center, Globus Med, Helix Laboratory Service, ABIA and many others. Prices for one study - from 340 rubles.