Interpretation of the results of a blood test for thyroid hormones. How to properly take a thyroid hormone test Blood test for thyroid hormones is normal

There is something common in the names “hormone” and “harmony”, although the roots are different and the meaning is different.

But, if we take into account that they are necessary for the harmonious functioning of the body to ensure normal metabolism - metabolism - to adequately replenish the energy expended by the body, then the comparison can be considered quite appropriate.

However, there will be no harmony if the norm is violated.

How our body works in conditions of struggle

Everything inside our body is subject to the law of conservation of energy. And since there is a law, someone must enforce it.

This “someone” is the main part of the brain – the hypothalamus. It is he who synchronizes the work of sympathetic and parasympathetic nerve fibers, along which impulses travel to the organs.

It is he who regulates the functioning of the endocrine glands, including the thyroid gland. It also helps maintain the fragile balance of the body.

Imagine you spot an enemy. Danger signal through optic nerves goes to the hypothalamus. It immediately activates sympathetic fibers.

You will feel your heart beating, your breathing quickening, and your palms becoming cold. This happened due to the instantaneous effect of a nerve impulse on the blood vessels, heart, and respiratory center.

The next thing he does is give commands to the glands. The thyroid gland will not be forgotten either.

The level of triiodothyronine will immediately increase, which will increase blood pressure and raise blood glucose levels, which will give the body additional energy to fight.

Why do we need nerve impulses and hormones? It’s just that the former reach the goal much faster, but they are not able to maintain the necessary background for a long time.

Hormones come to the rescue more slowly, but act much longer. The former can be compared to an ambulance, the latter to an emergency room.

Thyroid hormones are normal

The enemy got scared, ran away, everything comes into balance, including... Usually the level of its hormones in the blood is constant, but not always.

We already understand about stress, but not only does it cause fluctuations in thyroid hormones, but also illnesses.

But a number of other reasons force the anterior pituitary gland to increase the level of TSH:

• Stressful conditions
• or pituitary gland or thyroid gland
• Increased
• Adrenal problems
• Toxicosis
• Even cholecystectomy

A decrease in TSH levels is less common, but should also be alarming. This condition indicates either stress or the development of serious diseases, including secondary hypothyroidism.

The danger of cancer at an early stage is that it is asymptomatic or its manifestations are similar to the symptoms of pregnancy itself in the early stages.

Ultrasound and blood tests help in diagnosis. tumor markers, .

Prevention of thyroid diseases

It would seem easy to prevent the disease - simply eliminate the factors contributing to the development of the disease.

But in reality, it is not always possible to follow this advice. However, it will still be possible to do something.

If you can’t move from a city with an unfavorable environment, rent or buy a dacha in the area - regular walks in fresh, clean air will have a positive effect on the body’s resistance to disease.

It’s even easier to diversify your table with sea fish. Tasty and healthy - cod liver. Eat raw carrots and cabbage. Think about oatmeal more often. There is no need to even remind you about eggs and milk.

Most people are already tired of advice on a healthy lifestyle, giving up bad habits, and exercising.

But after reading about the thyroid gland at least in this article, having learned what is behind this disease, you will probably change your mind about the boring recommendations and reconsider your daily regimen.

Avoid stressful situations, be less nervous. If you cannot cope with this yourself, contact a neurologist or psychotherapist.

Learn auto-training that will definitely help you cope with yourself and the situation.

Treatment of the thyroid gland during pregnancy

In such a situation, therapy is carried out only conservatively, aimed at alleviating the woman’s condition and eliminating pain.

For the normal development of the child are used hormonal drugs and medications with high iodine content.

During pregnancy, removing the thyroid gland is strictly contraindicated, as this will negatively affect the course of pregnancy.

When the situation requires immediate surgical intervention, an operation to terminate the pregnancy is performed, since sudden hormonal changes threaten the fetus.

If a woman conceives a child immediately, without completing the subsequent course hormone therapy, the pregnancy will end in miscarriage.

The largest organ endocrine system human is the thyroid gland. It is here that important hormones such as T3 and T4 are produced. These substances take an active part in the formation of the functions of all organs and systems. Any malfunction of the thyroid gland leads to the development dangerous diseases. When and who needs to take a blood test for hormones? thyroid glands s?

What substances are classified as thyroid hormones?

What hormones belong to the thyroid gland? In many sources you can find information that hormone analysis thyroid gland includes a blood test for T3, T4, TSH and TPO. For this reason, many patients are sure that all these substances belong to thyroid hormones, but this is not true. The hormone TSH is a substance produced by the pituitary gland. TPO is not a hormone at all. This substance should be correctly called AT TPO. It is an antigen to the thyroid enzyme. Thus, thyroid hormones include only substances called T3 triiodothyronine and T4 thyroxine. However, all these substances are closely related to each other and it is for this reason that they are studied together.

T3 and T4 are thyroid hormones that are responsible for energy metabolism in our body. Even if you force a person to stand still, the energy exchange will not go away. Without these substances, our heart could not beat, our intestines would not work, the body would not produce excess heat, and all organs would simply stop.

TSH is a hormone produced by the pituitary gland in response to a deficiency of T3 and T4. The action of the hormone is based on increasing the production of T3 and T4. When TSH is released into the blood, it travels through the bloodstream to the thyroid gland. Then there can be two options for events: either the gland begins to synthesize hormones more intensely, or it begins to grow, increasing in volume.

If TSH in the blood increases, it is necessary to urgently identify the cause of T3 and T4 deficiency and take adequate measures to normalize their levels.

AT TPO are cells immune system, which, under certain malfunctions, begin to be actively produced and destroy a special thyroid enzyme responsible for the production of the hormones T3 and T4. With an increased level of antibodies in the blood, the risks of developing various pathologies increase significantly.

What tests need to be taken to evaluate the functioning of the thyroid gland? Experts say that first of all it is necessary to take the TSH and T4 hormones to understand the picture of the thyroid gland. However, normally it is necessary to be tested for all of the above substances so that the picture is as accurate as possible.

Why is analysis needed?

Testing for thyroid hormones is recommended for patients with certain complaints. This study is necessary to assess the functioning of the main human internal secretion organ. Today, thyroid diseases are in second place in frequency after diabetes mellitus. The health of organs such as the heart, gastrointestinal tract, as well as systems such as the vascular, reproductive and hematopoietic systems depends on the functionality of the thyroid gland. For this reason, the following specialists can recommend donating blood for hormones:

• Gynecologist.
• Endocrinologist.
• Therapist.
• Cardiologist.
• Psychiatrist.
• Immunologist, etc.

Indications for donating blood for thyroid hormones include:

• Takihardia.
• Tremor.
• Unexplained weight loss.
• Obesity.
• Memory loss.
• Skin problems.
• Increased sweating.
• Menstrual irregularities.
• Spontaneous miscarriages.
• Problems with conception.
• Problems in your sex life.
• Child development delay.
• Enlarged thyroid gland.
• Heterogeneity of thyroid tissue.

Most often, the test is prescribed when the patient undergoes a thyroid examination by an endocrinologist. Any structural changes in the tissues of this organ, such as nodularity, heterogeneity or an increase in volume, are the reason for prescribing tests for the thyroid gland. Diagnosis of abnormalities in this case is carried out with special care, because in some cases they can be symptoms of a disease such as thyroid cancer. When tests with abnormalities are received, the patient is prescribed additional diagnostics to identify the causes of the disorder.

Thyroid pathologies

There are more than a dozen thyroid diseases today. All of them can be divided into three main groups:

1. Pathologies caused by impaired hormone synthesis.
2. Pathologies caused by disruption of the brain.
3. Pathologies caused by dysfunction of thyroid hormones.

To the main reasons causing diseases The thyroid gland may include:

• Lack of iodine in food.
• Excess iodine in food.
• Hereditary factors.
• Poor absorption of vitamins due to gastrointestinal and liver diseases.
• Congenital disorders.
• Proliferation of gland tissue.

Preparing for analysis

Blood testing for thyroid hormones should be done at morning hours on empty stomach. In addition, preparation for the test should begin a month before the blood draw. If you are scheduled for a test in just a few days, you need to take urgent measures to ensure that the result does not turn out to be false, namely:

• Refuse to take any medicines. The test result can be affected by hormonal, iodine-containing, steroid and aspirin-containing medications. If refusal of drug therapy is impossible, you need to inform your doctor about this so that he takes this data into account when interpreting the analysis. Some medications can negatively affect hormone production.
• At least 8 hours must pass after the last meal. You are allowed to drink water before taking the test. It should just be clean, boiled. Mineral water drinking is not recommended.
• Before analysis, any physical exercise. If you are used to starting your day by jogging or working out at the gym, break this habit for a few days before taking the test.
• Stress and anxiety can also have a detrimental effect on the results of the study. You need to completely calm down. Also, on the day of analysis, you should not enter into conflicts with someone and sort things out. Your emotional state should be smooth.
• At least a week before you have to donate blood for hormones, give up any alcohol. This applies not only to strong drinks, but also to beer, cocktails, wine and other low-alcohol treats.

Many patients are interested in the question of where to take the test and how long the test is done. Today, you can get tested for thyroid hormones at any district clinic or medical center. The advantage of getting tested at the center is the quick receipt of results and the absence of queues, but of course you have to pay for this. How much the analysis costs in private centers should be found out at the institution. In the state clinic, if indicated, it is carried out free of charge. The analysis will be done on average from 24 hours to 5 days.

Decoding the results

The interpretation of tests for thyroid hormones should be carried out exclusively by the attending physician. Only a specialist can adequately assess the extent of the disorder and make the correct diagnosis.

Today, to assess the functioning of the thyroid gland, experts use the following average values:

It should be noted that different laboratories may perform blood tests using different equipment. In this case, the results may have different notation values.

Also, when deciphering the test, you need to take into account the gender and age of the patient, and therefore the diagnosis should be made only by an experienced doctor.

The levels of the hormones TSH and T4 are of particular importance in diagnosing diseases. Remember, only a doctor can accurately say whether your hormonal levels are normal or whether there are dangerous abnormalities.

Possible deviations

Any deviations in the thyroid gland are fraught with the development of dangerous diseases. The main deviation in the functioning of the thyroid gland is a decrease in its functions. This condition is medically called hypothyroidism. This deviation is conventionally divided into two stages, which have their own distinctive features in the analysis. The opposite disorder, called hyperthyroidism, is also common.

• Primary hypothyroidism is characterized by a slight decrease in the hormones T3 and T4 with high TSH.
• Secondary hypothyroidism can be detected by testing thyroid hormones for TSH and T4. In this case, T4 is always low and TSH is high.
• Hyperthyroidism can be suspected if the patient's TSH is low and the T3 and T4 hormones are highly elevated.

Treatment of deviations depends on the true causes of the disorder. When diagnosing a disease, the amount of hormones, the presence of pathologies, the weight and gender of the patient are taken into account. Analysis of thyroid-stimulating hormones is carried out using the patient’s venous blood. The analysis is valid only if the patient has followed all the rules for preparing for the test.

If there are deviations in the analysis, there is no need to immediately make terrible diagnoses. Most often, after changing the exercise schedule and giving up bad habits, the hormonal levels become normal again. For any unexplained illness, weight fluctuations or other symptoms of a disorder hormonal levels I urgently need to take a thyroid test. Remember, the sooner a deviation is identified, the easier it will be to bring your hormones in order. This can save you from many unpleasant diseases in the future.

In contact with

A patient’s independent visit to an endocrinologist is not a frequent occurrence, since the patient does not associate the thyroid gland with the symptoms of many diseases; however, even during the initial visit, tests for thyroid hormones will have to be done. It is important to understand the need for this procedure and under no circumstances neglect your health, since the law “better late than never” does not apply to the thyroid gland.

The process of producing thyroid hormones consists of five successive stages:

1. Absorption of iodides circulating in the blood by the thyroid gland.
2. Oxidation of iodides with the formation of free iodine molecules.
3. Iodization (saturation with iodine) of tyrosine residues in the composition of thyroglobulin.
4. The breakdown of thyroglobulin, the secretion of hormones T3 and T4 into the blood.
5. Conversion of T4 to T3 (occurs both in the thyroid gland and in peripheral tissues).

The main place of formation and storage of biological active substances of the thyroid gland are its functional units called follicles, which consist of special cells– thyrocytes.

Note. In some literature, thyrocytes are called thyroid A-cells, but in fact these two terms mean the same thing.

Thyrocytes synthesize the main hormones - thyroxine (T4) and triiodothyronine (T3). Their chemical formulas are almost identical except for the content of iodine atoms. The molecule of the first contains four of them, and the second - three, respectively.

Substances can be present in the blood in two states:

• free form (FT4 and FT3, from free) – biologically active;
• bound form (in combination with specific transport protein globules).

Important conditions for the formation of hormones are the presence of iodine and tyrosine (amino acid). First, thyroglobulin is formed in the follicles, which is a special protein that is collected and stored inside the follicle.

This substance provides a reserve from which ready-made hormones will be quickly produced when needed. After synthesis, they enter the bloodstream, where special thyroxine-binding transport proteins - albumin and globulin - are attached to them.

Thyroglobulin is a glycoprotein, i.e., a two-component compound of protein and carbohydrate molecules. Its molecular weight is approximately 600,000 daltons. This is a fairly large compound, so it is impossible for it to enter the blood in this state, but this can happen if there is pathological processes in an organ, for example, with thyroiditis, when the integrity of the follicles is destroyed.

In order for the formation of basic hormones to proceed correctly and in the required quantities, it is important that pure (“elementary”) iodine is present in the blood, which is formed during the oxidation of that supplied with food or from environment substances in the form of iodide. First, one or two iodine atoms can associate with tyrosine, thus producing monoiodotyrosine and iodotyrosine, which are the precursors of functionally active thyroid hormones. Then these molecules combine and form thyroxine (a complex of two diiodotyrosine molecules) or triiodotyrosine (an association of monoiodotyrosine and diiodotyrosine).

Calcitonin is produced by parafollicular cells or C-cells of the thyroid gland. This is an essential element for the exchange and absorption of calcium and phosphorus ions, and is extremely important for the normal functioning of the structural units of bone tissue - osteoblasts.

Note. Calcitonin is significantly different in structure from other thyroid hormones - its molecule is a long chain consisting of 32 amino acids (polypeptide).

What are the hormones responsible for and need to be tested?

So, what are thyroid-stimulating substances produced by the thyroid gland responsible for:

• growth and development of the fetus (formation of the central nervous system, cardiovascular, respiratory and other systems);
• increased intestinal contractility;
• increased myocardial oxygen demand;
• increase in the number of heart contractions;
• increase in cardiac conduction impulses;
• maintaining normal level oxygen and carbon dioxide;
• ensuring normal functioning of the respiratory center;
• influence the destruction of bone tissue and bone formation;
• increase the synthesis of structural proteins in muscles.

Thus, an increase or decrease in synthesis, in a word, a deviation from the norm, will cause problems in almost all body systems. But why is it often not enough to know the meaning of T3 and T4, and doctors prescribe more and more tests.

Hormone TSH

Although this hormone is not produced directly in the thyroid gland, it is produced exclusively for it. This is a pituitary hormone that is synthesized when there is a decrease in the thyroid hormones T4 and T3.

Together with the bloodstream, it enters the thyroid gland at special receptors and affects them.

When interacting with receptors, the following occurs:

1. The thyroid gland begins to actively synthesize the hormones T3 and T4.
2. Enlargement of the thyroid gland by stimulating the growth of tissues of this organ.

Determining an acceptable TSH hormone level is the first and most important indicator of thyroid health.

T4 hormone

This is the most primary hormone of the thyroid group. It accounts for 90% of all hormones synthesized in the thyroid gland.

Thyroxine consists of four iodine atoms, which is why its name contains the number 4. Sometimes you can see in the direction for analysis - free T4 or T3. This is a more refined analysis.

T3 hormone

This hormone is the most important in thyroid hormones. Only 10% of the T3 hormone is synthesized in the thyroid gland. The remaining 90% is formed by removing one iodine atom from the T4 hormone. In this connection, the T4 hormone turns into a much more energy-intensive and active T3.

Triiodothyronine reflects all the main functions of the thyroid gland. T4 and T3 - are synthesized in the body to control and manage energy metabolism. Contractions of the heart muscle, the work of the sweat glands, the process of digesting food and its movement through the gastrointestinal tract are processes that require energy. It is these active processes that T3 and T4 control.

Sometimes you can also see different ATs in the analysis. This is an antibody test that is prescribed to a patient if autoimmune pathologies are suspected.

Calcitonin

This hormone is produced in the C cells of the thyroid gland, located next to the follicles. The origin of these cells is neuroendocrine; they are formed in the pancreas in the fetal period.

In terms of number, the C-cells that secrete calcitonin are much inferior to the B and C-cells that enter the thyroid follicles. Based on information in various medical literature, calcitonin is considered a substance that blocks the work of parathyroid hormone, but the effect of calcitonin is several times weaker than parathyroid hormone. In addition, calcitonin is a tumor marker for thyroid cancer.

Calcitonin levels change in the following cases:

• osteoporosis;
• anemia;
• thyroid cancer;
• prostate, breast or respiratory cancer.

AT to TPO

An antibody test in the blood is used as an additional marker to determine if the thyroid gland is malfunctioning. These antibodies are produced against thyroid peroxidase. This enzyme is involved in the synthesis of thyroid hormones.

AT to TG

This type of antibody is produced by the lymph nodes.

It is present in a blood test only in patients with the following diseases:

• autoimmune thyroiditis;
• diffuse toxic goiter.

Also Special attention Increased levels of these antibodies are given to patients diagnosed with papillary and follicular thyroid cancer. This is a significant tumor marker for this disease.

AT to rTSH

These antibodies are produced in the body of a patient with diffuse toxic goiter. and are prescribed only if this disease is suspected. The level of antibodies in a blood test determines the possibility drug treatment or indications for surgery.

Why is the hypothalamus attracted?

More often, endocrinologists require an analysis of the hormones T3, T4, TSH, but if everything is clear with the first ones, then TSH belongs to the hypothalamic-pituitary system, and at first glance, it’s far-fetched, but this is not so. The thing is that it is TSH that is responsible for the production of T3 and T4, under feedback control (the more triiodothyronine and thyroxine, the lower the TSH level).

However, like any other system in the body, the production of T3 and T4 can fail, so it is important to know whether an increase or decrease in the level of T3 and T4 is associated with the functioning of the hypothalamus or not.

What if you just take a TSH test?

Logically, if the hypothalamic-pituitary system fails, then estimates TSH level will be sufficient. But alas, this is not the case, since in addition to the hypothalamus, the thyroid gland uses an independent system to control the level of thyroxine and triiodothyronine release, so the TSH level may not change in some types of pathologies.

Search for free T3 and T4

An analysis of thyroid hormones may include the value of free T3 and T4; in essence, these are the same substances. But why are they defined in separate parameters?

The thing is that thyroid-stimulating hormones do not enter the blood in pure form, but in symbiosis with transport proteins; in the laboratory determination of T3, T4, they are determined, however, 0.04% of thyroxine and 4% of triiodothyronine are not associated with proteins, free values refer specifically to them.

Note! The level of protein-bound triiodothyronine and thyroxine may well change if the patient takes certain medicines, therefore, data obtained without determining free T4 and T3 may be unreliable.

It’s decided - we rent out the free ones

Despite the fact that it is by free hormones that people are judged functional work thyroid gland, donating blood only for free values ​​is not enough. Here we are talking about binding proteins that can be synthesized by the body in larger or smaller quantities.

So, with increased production of one of the binding proteins, the indicators of unbound T3, T4 will be normal, but general values will increase, and vice versa. When might this happen?

Increased production:

• pregnancy;
• estrogen treatment;
• acute phase of infectious hepatitis.

Reduced protein synthesis:

• severe somatic diseases;
• nephrotic syndrome;
• use of glucocorticosteroids or androgenic drugs.

It was ours, it became someone else's

A separate link in the laboratory diagnosis of the thyroid gland is the analysis of hormones and TPO, the norm of which begins with the number zero. The decoding of the abbreviation sounds like: determination of antibodies to thyroid peroxidase. If translated into accessible language, this is the definition of specific substances that are released when the body considers the thyroid gland foreign.

Such antibodies appear only in autoimmune diseases, so they are prescribed extremely rarely. The upper limit of normal reaches 34 IU/ml; it does not depend on the patient’s age, unlike other values.

Resolving complex issues

If for some reason the patient decides to take tests on his own, then, frankly speaking, it is not worth doing. Only a doctor has the right to make a decision on laboratory diagnostics independently, taking into account the patient’s diseases, history and complaints, otherwise the interpretation may turn out to be incorrect, and do-it-yourself treatment will bring a lot of trouble.

Such symptoms may prompt a specialist to force the patient to donate blood for testing:

• tachycardia;
• hand trembling;
• weight loss/gain;
• cold intolerance;
• exophthalmos or visual disturbances;
• photophobia;
• dry skin, hair loss;
• constipation, diarrhea;
• absence of menstruation;
• weakness, fatigue, insomnia;
• swelling.

Oddly enough, patients may not look at all like in the photo, since disorders of the endocrine glands can manifest themselves with the symptoms described above, without any external manifestations.

The patient got ready

Without a doubt, the doctor is obliged to talk about the basic rules, and the patient must take this into account before going to the laboratory, but if this does not happen, then it is worth clarifying what and how.

1. Choosing a laboratory. The simplest thing is to get tested at the very clinic to which the patient is assigned, but, as practice shows, this is not always possible. Patients most often choose the laboratory they trust more or follow the doctor’s instructions, both decisions are rational.
2. Bad habits. Smokers will have to put down cigarettes 3 hours before the test. It is better not to drink alcohol the day before for moral and ethical reasons rather than because of data distortion.
3. Nutrition. You will also have to refuse food; if you cannot come to the procedure on an empty stomach, then you must abstain from food for at least 2-3 hours. At the same time, drinking pure still water is quite acceptable.
4. Overvoltage. During the two days before laboratory diagnostics, it is advisable not to overdo it both physically and emotionally; the advice is relative, but it may affect the results.
5. Taking medications. As mentioned earlier, many medications affect the results, so first of all, you need to decide with a specialist which drugs need to be excluded 2 days before the test, and whether this is necessary.

Important! Choosing a laboratory is a responsible undertaking, since each repeat analysis will need to be taken there. This is due to differences in diagnostic methods, so even reference (normal) values ​​may differ.

Taking blood for analysis

Despite the fact that the production of the substances under study is concentrated in the thyroid gland and hypothalamus, hormones bound to proteins or in free form circulate in the bloodstream. It is for this reason that they do not do anything supernatural with the patient, but only collect venous blood.

A certain category of patients cannot leave the house, or even their bed, so for such people blood is drawn at home. Unfortunately, not all laboratories provide home visits, but this is possible. In severe cases, it is necessary to more carefully approach the issue of choosing a laboratory or transporting the patient to the place of blood sampling.

The procedure itself is quite primitive and usually does not take more than 5-10 minutes. The instructions according to which the nurse draws blood have not changed for several years, so you should not be scared when you see a very young specialist; even a medical student can perform such manipulation.

Take it again

If any pathology is detected, the patient will need to undergo repeated laboratory test during or after prescribed treatment. There is no point in repeating blood tests for T4 and T4 more often than once every 2 months.

It will definitely not be possible to see the dynamics earlier than in a week, since during this time the level simply did not have time to change.

And then something went wrong

Undoubtedly, distorted results do occur in practice, and not all of them can be avoided; patients who sincerely care about their health need to be aware of what can cause deviations from the norm.

1. Hemolysis. The blood simply does not reach the laboratory in a reliable form; this happens extremely rarely. It is simply impossible to carry out diagnostics with such blood, so instead of the result you will receive a message that the blood needs to be re-dated.
2. Fat level. If the patient has biochemical analysis If there was a pronounced disturbance of lipid metabolism, then you will have to wait.
3. Pregnancy. In the 3rd trimester, the TSH level may increase and still remain normal for a particular woman. Regarding T3 and T4, it must be said that they can increase in any trimester of pregnancy.
4. Time. As a laboratory, the timing of the collection is also important, levels can vary throughout the day, so it is preferable to give blood for monitoring at the same time during the day.
5. Medicines and narcotics. In addition to medications, narcotic substances, including morphine, heroin, methadone and others, affect the results. Regardless of whether the patient uses such substances for medical reasons or without them, the results may be distorted.

What about the norms?

As mentioned earlier, standards may differ depending on the laboratory, most often the difference is insignificant, so it is worth giving approximate criteria for reference values ​​that directly depend on age.

Important! If the patient has received an analysis for TSH and T4 hormones, the norm of which differs from the values ​​in the table, but coincides with the reference values ​​​​indicated on the laboratory form, then the latter are considered priority. The same applies to other thyroid-stimulating hormones.

Level up

If T3 and T4 begin, for a number of reasons, to be released more intensely than is necessary for a normally functioning body, a pathological condition called thyrotoxicosis is observed and manifests itself even at the initial stage with the following symptoms:

• tremor;
• sweating;
• nervousness;
• feeling of heat;
• irritability.

With further progression of the disease, arrhythmias and heart failure begin to develop. At timely diagnosis and treatment, in most cases, medication is sufficient to relieve this condition.

In severe and advanced cases, it is impossible to do without surgery with possible subsequent therapy with radioactive iodine isotopes.

Downgrade

The opposite situation, when there is not enough thyroid hormone, is called hypothyroidism. Its manifestations are in many ways the opposite of the previous pathological condition.

Hypothyroidism is characterized by:

1. Lethargy.
2. Weakness.
3. Chilliness.
4. Swelling.
5. Depression.
6. Drowsiness.
7. Weakening of potency.
8. Decline in performance.
9. Menstrual disorder.
10. Reduced likelihood of conception.

This state can be compared to winter, when everything in nature falls asleep. In this condition, not only basic tests are done for thyroid hormones, but also for antibodies to thyroid peroxidase.

How is the diagnosis made?

Even with all the information, it is very difficult to make a diagnosis on your own without medical education. You can study for yourself which hormonal indicators are associated with which diseases, but you should not rely on such information.

Although, sometimes this can help avoid the “doctor” trying to “cure” the “disease”. So such information, perhaps, will not be superfluous.

So:

1. Hyperthyroidism— T3 and T4 are elevated, TSH AT-TG is low, AT-TPO is normal. With this disease, the thyroid gland begins to produce completely different types of hormones, to which, in turn, the pituitary gland begins to respond. Against this background, the TSH concentration drops.
2. Primary hypothyroidism– T3 and T4 are reduced, AT-TG and TSH are increased, AT-TPO is normal. In this case, the pituitary gland reduces its activity, which causes an increase in TSH and a decrease in the concentration of other hormones.
3. Hypothyroidism secondary– AT-TG and AT-TPO are normal, and T3, T4, TSH are reduced. Disturbances occur in all functions of the endocrine system, and the pituitary gland becomes less active. Against this background, the hormones T3 and T4 cannot be produced and developed normally.
4. Autoimmune thyroiditis– AT-TG and TA-TPO are increased, but other hormones can either remain normal or decrease/increase. The immune system produces antibodies, but the thyroid gland at this time begins to become active or “fall asleep,” which is why the concentration of hormones begins to change.

The thyroid gland is expecting a miracle

During pregnancy, the synthesis of hormones in a woman’s body may change, or may remain the same as before. If there is any suspicion, the doctor must react in time.

A pregnant woman needs to be registered with an endocrinologist only if deviations from the norm have been identified. Read more about hormonal changes during pregnancy in the video in this article.

Pregnancy is a difficult period in terms of restructuring the body. The attentive attitude of doctors towards a pregnant woman guarantees proper development fetus, and control of thyroid-stimulating hormones is actually a prerequisite.

Table: Reference values ​​of thyroid hormones during pregnancy:

Paid or free healthcare

Many patients have a natural question about whether it is worth choosing paid laboratories, or whether free medicine provides services no worse. This is complicated by the fact that the price of studying the level of thyroid-stimulating hormones is quite high, and not everyone can afford it.

Apart from the methods of research and the time when the results will be ready, laboratories are almost no different from each other. If a patient has used the laboratory’s services for several years and was quite satisfied with the quality of service, then there is no point in changing it, regardless of whether the clinic is budgetary or private.

Why getting tested on time is important

The thyroid gland is one of the most important hormone-producing organs; it affects almost all organs and systems, affects the development of the fetus and child, so any deviation from the norm can lead to dire consequences.

A timely test for hormones T3, T4, TSH is a guarantee of timely treatment for many diseases.

We asked - we answer

Can't come under control

I am undergoing treatment from an endocrinologist, while taking L-thyroxine. Tomorrow I need to come to have my TSH and T4 checked, but I ended up in the traumatology department with a broken leg. Now there is no way to see an endocrinologist. How to take L-thyroxine now, because the dose has not yet been fully selected.

Stop panicking

Be sure to inform your attending traumatologist that you are taking L-thyroxine; he will schedule a consultation with an endocrinologist. The doctor will come to the consultation himself and decide on the spot whether to conduct a TSH and T4 examination or not, and if necessary, he will adjust the dose of the drug.

Already tired of giving up

Every month I take tests for TSH, T4, T3, general and free, sometimes all together, sometimes separately, but to no avail. Total T3 and T4 are constantly elevated, but free ones are normal.

I heard that the functioning of the thyroid gland can be judged by free T3 and T4, then it turns out that I am quite healthy. Why do they send me to different laboratories so often, although no treatment is prescribed. I'm just tired of all this, can I just not show up for the next control?

We'll have to endure

Such results are possible if thyroxine-binding globulin does not work properly, but it is impossible to say for sure without the results of hand examinations and an adequate examination. Therefore, the only right decision for you would be to contact another endocrinologist; you may have to take tests again, but you definitely shouldn’t ignore the problem completely. remember, that increased level thyroxine and triiodothyronine will not lead to anything good.

Refused to examine

I spent a long time (1 year) undergoing treatment for heroin addiction abroad, but returned only a month ago. I recently went to see a therapist about insomnia, and the doctor sent me to an endocrinologist with suspected thyroid problems. I told the endocrinologist everything in good faith, and about the withdrawal syndrome and replacement drugs that I took six months ago, but he waved his hand and said that there was no point in taking tests from drug addicts.

I wrote on the card that everything was fine. I haven’t taken drugs for a year now, and I haven’t taken replacement drugs for six months, and in general, I haven’t taken any medications except Kagocel for two months. When can I get my thyroid checked? Is this really a death sentence now, and no one will treat me?

Need to check now

Taking heroin does affect the research results, just like heroin replacement drugs, but judging by the timing, they will not have any effect at the moment. Feel free to go to the endocrinologist again or get tested at private clinic, if there are any changes, they will be reliable.

Based on these results, treatment should be carried out (or not carried out). Problems with insomnia can be associated with other diseases, but if the therapist suspects something, then donating venous blood is simply necessary, and the sooner the better. Perhaps the treatment will also be carried out by a therapist, since the endocrinologist refuses to treat you.

Thyroid examination when planning pregnancy

Christina, 25 years old: I’m planning my first pregnancy, I started being examined by doctors. I remember that earlier, as a teenager, I had problems with the thyroid gland (it seems like a goiter), I took Iodomarin for a long time.

Now I have no complaints, I feel good. What thyroid tests would you recommend me to take?

Hello! If you do not have any complaints, to plan a pregnancy it is enough to take two tests - for free thyroxine (T4) and TSH. At the same time, remember that the targets TSH values for women preparing to bear a baby, they are slightly different from the standard and amount to 1.5-2.5 mU/l. Contact your endocrinologist if your result does not correspond to these values. In addition, you will need to consult a doctor if thyroxine is higher or lower than normal.

Subclinical hypothyroidism

Tatyana, 36 years old: Hello! Two years ago I took hormone tests for the first time. The results were as follows: T4 - 1.33, TSH - 3.73, anti-TPO - 299.82. Although latest analysis was clearly above the norm, the doctor did not prescribe anything for me at that time, advising me to simply undergo repeated examinations periodically.

Recently I began to swell - mainly my face (eyes) and fingers. The weight climbed up. I took the tests again: T4 - 1.06, TSH - 18.92, anti-TPO - 299.82. Now the endocrinologist prescribed me to take Eutirox 50 mg and retake the test in a month. Is this true? What should I do about elevated TPO antibodies?

Hello! Based on your tests, you can be diagnosed with hypothyroidism: TSH exceeds physiological values ​​by almost three times. Although T4 is still within the normal range, without treatment it would begin to decline.

Your doctor’s prescriptions are absolutely correct: 50 mcg of Eutirox will make up for the resulting lack of thyroid hormones, and TSH will gradually decrease to normal values. Since the dosage that suits you is just being selected, do not forget to take control tests in a month.

As for the increased AT to TPO, I would advise you to simply not control their level anymore. If antibodies are already present in the body, reduce their concentration modern means impossible. But they do not affect treatment tactics in any way.

The well-known thyroid gland is one of the most important components of the endocrine system and belongs to the category of endocrine glands. It is she who synthesizes a number of hormones that are so important for the human body, responsible for homeostasis and maintaining it at the correct level.

Various disorders of the thyroid gland today are diagnosed in almost half of people, but most often women suffer from ailments in this area. In this article you will learn what tests you need to take for thyroid hormones, you will find information about deciphering the results, features of the analysis during pregnancy and the reasons for deviations from the norm.

Indications for analysis

The hormones of this gland are special substances characterized by high biological activity. Their synthesis occurs not only in the thyroid gland, but also in the pituitary gland. These hormones are responsible for many functions of the body, for example, the metabolism of carbohydrates, fats and proteins, sexual function, emotional and mental state, as well as the functioning of many systems, in particular the gastrointestinal tract and cardiovascular.

Deviations from the norm in any direction indicate the presence of disturbances in the functioning of the body due to the improper functioning of this gland, while the production of hormones can be either insufficient or excessive.

Most often, indications for prescribing a hormone test are:

Which thyroid hormones should be tested?

When conducting a test for thyroid hormones, you need to take several parameters at once:

• Thyrotropin(thyroid-stimulating hormone or TSH), which is a hormone of the pituitary gland. It is this hormone that has a stimulating effect on the thyroid gland and its production of such important hormones as T4 and T3. If the pituitary gland works normally, then in case of disturbances in the functioning of the thyroid gland, a change in the concentration of the hormone may be observed downward when the gland is overworking, and upward when the gland is working insufficiently.
• Free triiodothyronine (T3 free), which is a thyroid hormone responsible for the metabolic processes of oxygen in cells and tissues.
• Free thyroxine (T4 free), which is one of the main hormones synthesized by the thyroid gland. This hormone in the body is responsible for the production of protein and is a stimulator of this process.

When testing the blood, AT-TG is also determined - antibodies to thyroglobulin. This substance is a special antibody to a special protein, which is a precursor to thyroid hormones.

AT-TG is very important in diagnosis, since it allows you to identify diseases of the thyroid gland that are autoimmune in nature, for example, autoimmune thyroiditis of the atrophic type, Hashimoto's disease, as well as toxic goiter of the diffuse type.

The analysis also detects AT-TPO - antibodies to thyroid peroxidase, sometimes called microsomal antibodies. This test is the most sensitive in detecting disorders of the thyroid gland of an autoimmune nature, since the substance is a special autoantibody to a cellular enzyme.

Now you know what tests are done for thyroid hormones - let's move on to deciphering the results of the study.

Decoding the research results

It is important that only an experienced doctor interpret the results of such a study.

You should not try to decipher the analysis of thyroid hormones yourself, since only a qualified specialist - an endocrinologist - can make an accurate diagnosis.

The results may vary, for example:

Hormonal norm

In conditions and opportunities modern medicine It is no longer relevant to talk about any exact and strict standards for thyroid hormones. Each laboratory sets its own normal values ​​for the studied parameters of blood and other materials for analysis.

As a rule, the values ​​of standards for each laboratory are determined by the features of the installed equipment, models of research devices, their settings, as well as the reagents used.

The values ​​are based on established international standards, but each laboratory makes its own adjustments to the normal values. Although the difference in standards among many laboratories is small, in some situations it can be quite significant and create a false impression of the patient's condition, as well as lead to an incorrect diagnosis.

The international standard for thyroid-stimulating hormone concentration is considered to be a range of values ​​from 0.4 to 4.0 µIU/ml.

The norm of the T4 hormone in most laboratories ranges from 9 to 19 pmol/l.

The T3 norm according to international standards ranges from 2.6 to 5.7 pmol/l. Determining the concentration of this particular hormone is the most difficult when examining the blood of patients, so most laboratory errors occur precisely in this indicator.

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The normal level of antibodies to AT-TPO is usually from 0 to 20 IU/l, but in some laboratories there are values ​​from 0 to 120 IU/l, as well as other data considered normal. Therefore, the forms of each laboratory should always indicate the established standards.

The normal value of antibodies to thyroglobulin ranges from 0 to 4.11 IU/l.

It is also important to remember that the norms largely depend on the patient’s age, as well as his gender.

Reasons for deviations

An important point in diagnosing many body conditions and diseases is the simultaneous interpretation of all hormone analysis indicators. Exactly systems approach to study the results gives doctors a complete picture of the work of the patient’s pituitary gland and thyroid gland.

The presence of obvious hypothyroidism can be said when TSH concentrations are higher than normal and a decrease in the T4 hormone is observed. If the T4 hormone is within normal values, this may indicate that hypothyroidism occurs in a latent form. But in any of these cases, it should be remembered that such values ​​indicate that the thyroid gland is literally working to the limit.

The important point is that if, against the background of an increase in the TSH hormone, there are no deviations in the T4 indicator, this indicates a special condition of the thyroid gland, its euthyroid status, and this poses a serious threat to the occurrence of many complex diseases, so the patient needs constant medical supervision .

An increase in TSH may occur due to:

• Various somatic or mental disorders.
• The presence of hypothyroidism, which has various etiologies.
• Pathologies or tumors of the pituitary gland.
• Disorders of TSH production.
• Insufficiency of the adrenal glands.
• Preclampsia.
• Thyroiditis.
• The presence of tumors in the body, for example, mammary glands or lungs.

But, in addition to an increase, TSH may also be decreased, which most often occurs due to frequent stressful situations, as well as the presence of mental disorders. A decrease is also observed in cases of damage to the pituitary gland, its injuries or necrosis, as well as in the presence of thyrotoxicosis. To check the functioning of the thyroid gland, you need to take a blood test for hormones, the list of which is given above.

Analysis of thyroid hormones during pregnancy

During the period of gestation, hormonal levels in female body changes greatly, which must be taken into account when interpreting research results. The chorion, and later the placenta, which develops in the uterus along with the baby, produces the hormone hCG, which has an effect on the thyroid gland similar to TSH.

During pregnancy, a large volume of hCG enters the woman’s blood, stimulating the functioning of the gland, and the synthesis of TSH decreases naturally, which is completely normal.

Since the TSH level is unstable during pregnancy, the concentration of free T4 becomes an important point for diagnosis. It is the free form of this hormone that in this case has diagnostic value.

In particular, if, against the background of a decrease in TSH, the level of T4 (free) remains normal, this is an indicator of a normal (physiological) pregnancy.

If, against the background of decreased TSH, a slight increase in T4 is detected, this does not indicate the exact presence of pathologies, but indicates that the woman has similar risks, and therefore it is necessary to monitor the development of pregnancy. But if at the same time free T4 has a significant excess and at the same time the concentration of T3 is increased, the woman requires urgent help from an endocrinologist and normalization of hormone levels.

An important point is that the total T4 indicator during pregnancy has no diagnostic value, since during this period its value is always increased, but this is not a pathology.

How to prepare for analysis

Today on the Internet you can find many recommendations for preparing for such tests, but most of the information is very contradictory and unreliable. To prepare for research in order to obtain true results, you need to follow a few very simple rules.

• You don't have to restrict yourself in diet and maintain an interval of 10–12 hours between the last meal and the time of blood sampling. Nutrition does not affect the level of thyroid hormones. Their concentration in the blood is stable, so you can take the test immediately after eating. Of course, in the event that no other research is required.
• You can take a hormone test at any time during the day.. During the day, the concentration of TSH changes, but these fluctuations are insignificant and cannot have a significant role in the diagnosis. Of course, if other tests are required to be taken at the same time as testing hormone levels, then you must come for the blood draw in the morning.

There are often recommendations that if a person is taking medications containing hormones, then their use should be stopped about a month before the test. But such a measure can negatively affect a person’s condition and cause serious harm to health.

In addition, in most cases, the study is carried out precisely against the background of taking such drugs, in order to assess the effectiveness of the treatment.

One point should be taken into account - you should not take medications before blood sampling, directly on the day of the test.

You can also find recommendations that you should stop taking medications containing iodine at least a week before the test. But such drugs do not affect hormone levels in any way. Iodine entering the body is processed in the thyroid gland, but does not affect the activity of its work and the synthesis of hormones.

For women, an important point is that the level of hormones in this group does not depend on a specific day of the menstrual cycle, so you can take the test on any day without subsequent adjustment of the result for a specific day.

The menstrual cycle, of course, affects hormonal levels, but only in relation to sex hormones, which are not related to the hormones of the pituitary gland and thyroid gland.

Very often you come across articles on the Internet on the topic “Blood test for thyroid hormones - T4, TSH, T3, TPO.” Such articles show ignorance of the issue by the authors, since thyroid-stimulating hormone (TSH) is actually a hormone of the pituitary gland - a small endocrine gland located in the brain and controls the work of all other endocrine organs, including the thyroid gland. The T4 hormone (thyroxine, tetraiodothyronine) and the T3 hormone (triiodothyronine) are really thyroid hormones, i.e. thyroid hormones produced by this organ at the command of the hormone TSH. TPO (more correctly written “anti-TPO” or “anti-thyroid peroxidase”) is not a hormone at all, but an antibody produced by the immune system against one of the important enzymes of the thyroid gland. However, most often these indicators are studied together, since they are closely related to each other, so we will talk here about all of these important substances Oh.

Hormone TSH(short for "thyroid-stimulating hormone", i.e. hormone intended for the thyroid gland) is produced by pituitary cells in response to a decrease in the level of thyroid hormones T4 and T3 in the blood. TSH is carried in the blood to thyroid cells and interacts with a special area on the surface of the cells called the TSH receptor.
When thyroid-stimulating hormone acts on the TSH receptor, two types of effects occur:

• strengthening the function of thyroid cells, i.e. The thyroid gland, at the “command” of TSH, more actively produces the hormones T4 and T3;
• strengthening the growth processes of thyroid tissue with an increase in the total volume of this organ.

TSH is a hormone whose level in the blood indicates normal thyroid function. It is the main one in the entire “family” of thyroid hormones; it must be taken during any blood test for hormones.

Thyroid hormones(from glandula thyroidea - thyroid gland, i.e. thyroid hormones) T4 and T3 designed in the body to control basic metabolism - i.e. the energy exchange that should occur in the human body even in the absence of any work. If you place a person on a flat horizontal surface in a room with a temperature of 36.6 degrees and ask him not to move, the person will still expend energy. This energy will be spent on contracting the heart, passing nerve impulses along the nerves, evaporation of moisture, intestinal peristalsis and other processes without which a person simply cannot live. The activity of these processes is controlled by thyroid hormones. Without the influence of these important substances, a person simply cannot live, since the basis, the basis for the manifestation of the functions of other hormones, is not created.

T4 hormone (thyroxine, tetraiodothyronine)– the main hormone of the thyroid gland, making up 90% of the hormones produced by the gland. The number “four” in its name appears due to the fact that the molecule of the hormone thyroxine contains four iodine atoms. Thyroxine has a very simple structure - it is formed from two residues of the amino acid thyroxine, obtained by humans from protein, and four iodine atoms. The thyroid gland is the main consumer of iodine in the human body - and all this iodine is used to produce hormones.

T3 hormone (triiodothyronine)– the second hormone of the thyroid gland. Its activity is 10 times higher than the activity of thyroxine. 10% of the T3 hormone is secreted by the cells of the thyroid gland, and the remaining 90% is formed in all tissues of the human body from thyroxine by “tearing off” one iodine atom. Once this “extra” atom is removed, like pulling the pin out of a grenade, the T4 hormone is converted into 10 times more active T3. It is triiodothyronine that has all the main effects of thyroid hormones. Some doctors even call thyroxine a “prohormone,” emphasizing that it is not the main one in our body, it is only a precursor of the main hormone, and only its conversion into triiodothyronine allows thyroid function to manifest itself.

You can often find notes in doctors’ recommendations and laboratory reports “free T4 hormone” or "free hormone T3". In another way, the same thing is written as FT4 or FT3 (from free T4 or free T3 - that is, free hormones T4 and T3). The fact is that in the blood the overwhelming majority of thyroid hormones are in a protein-bound state. As soon as thyroxine or triiodothyronine is released into the blood by thyroid cells, they are immediately “picked up” by thyroxine-binding globulin (TBG), a special carrier protein that, like a train, “carries” hormones through the blood and “unloads” them in those places where they are needed. Protein-bound hormones are inactive; they begin to act only after they “unhook” from the protein and become “free.” The fraction of hormones not bound to proteins is called free thyroid hormones - it is this fraction that has the main biological effects. Therefore, if the doctor recommended you a blood test for thyroid hormones and indicated “TSH + T4 hormones” in it, it is better to take the free T4 hormone, since this test is more important and accurate.

However, not only hormones are important in diagnosis. Antibodies against thyroid tissue- the second important indicator required by endocrinologists to establish a diagnosis.
Antibodies are of three types:

• antibodies to thyroid peroxidase (abbreviated as “anti-TPO”, “anti-TPO”),
• antibodies to thyroglobulin (abbreviated as “AT to TG”, “antibodies to TG”),
• antibodies to the TSH receptor (abbreviated as “AT to rTSG”, “antibodies to rTSG” - not to be confused with “AT to TG”!).

Antibodies to TPO are produced by cells of the human immune system against one of the main enzymes of the thyroid gland - thyroid peroxidase, which is directly involved in the production of the hormones T4 and T3. Antibodies to TPO are elevated in 7-10% of women and 3-5% of men on our planet. In some cases, an increase in antibodies to TPO does not lead to any diseases, in others it is accompanied by a decrease in the level of hormones T4 and T3. It has been proven that in a situation where antibodies to TPO are elevated, decreased function and problems with thyroid hormones are 4-5 times more common than in people without increased antibodies. Therefore, a blood test for antibodies is used as an auxiliary test in the diagnosis of inflammatory autoimmune diseases of the thyroid gland (autoimmune thyroiditis, diffuse toxic goiter).

Antibodies to thyroglobulin are also produced by lymphocytes of the human immune system, but their increase occurs much less frequently than an increase in the titer of antibodies to TPO - no more often than in 5% of women and 3% of men. These antibodies are elevated in patients autoimmune thyroiditis and diffuse toxic goiter, however, antibodies to TG are of greatest importance in the treatment of papillary and follicular thyroid cancer. These types of thyroid cancer produce thyroglobulin, a special iodine-containing protein that is a precursor to the T4 and T3 hormones in the body.

Thyroglobulin in the human body can only be produced by the thyroid gland and cells of papillary and follicular cancer, therefore, after removal of the thyroid gland and tumor, the level of thyroglobulin in the blood should become close to zero. If thyroglobulin does not decrease after surgery, this indicates tumor recurrence, therefore this protein is the most important tumor marker in patients with a removed thyroid gland. However, in patients with elevated antibodies to thyroglobulin, the antibodies bind to the thyroglobulin molecule and change its shape so that it becomes undetectable by laboratory analyzers. In this regard, in patients with an increased titer of antibodies to TG, the level of thyroglobulin cannot be completely trusted. A study of the antibody titer to TG should always be carried out simultaneously with an analysis for thyroglobulin - otherwise the test results may be interpreted incorrectly.

It is important to note that the thyroglobulin test should not be used in patients with a preserved thyroid gland. In a patient with a preserved thyroid gland, the level of thyroglobulin in the blood depends only on the volume of the thyroid gland, the size of the thyroid nodules and the presence of an inflammatory process in the gland tissue. Many medical centers prescribe a thyroglobulin test to their patients, but this is simply a way to increase the patient’s costs - thyroglobulin has no clinical significance before removal of the thyroid gland.

Unlike thyroglobulin, calcitonin– this is indeed a very important tumor marker. It should be determined in all patients with thyroid nodules in order to detect medullary thyroid cancer. This type of cancer (also called C-cell thyroid cancer) is formed from type C cells that actively produce calcitonin.

Medullary cancer- Very dangerous form a tumor that is “not afraid” radiation therapy and is practically not treated with chemotherapy (except for the most modern drugs from the group of tyrosine kinase inhibitors). The only thing that medullary cancer is “afraid of” is the time of surgery, so its early detection is the key to the success of subsequent treatment. In large scientific studies conducted in Italy and the USA, it was shown that when performing a calcitonin test on all patients with thyroid nodules, medullary cancer is unexpectedly discovered in 1 case out of 300, and most often at a very early stage. The result of these studies was the recommendation of the European Thyroid Association to measure calcitonin once in all patients with thyroid nodules.

The last indicator we need to talk about is antibodies to TSH receptors. Antibodies to TSH receptors are determined in patients with diffuse toxic goiter (Graves' disease, Graves' disease) in order to determine the likelihood of curing the disease during drug therapy. Scientific studies have shown that a high level of antibodies to TSH receptors indicates a low likelihood of a patient being cured while taking the pills. That is why high antibodies to TSH receptors are a predictor of poor outcome of the disease and often indicate the need for the patient to undergo surgical treatment. At the same time, base recommendations for surgery only on high level antibodies to TSH receptors is incorrect - to make a decision on treatment tactics, it is necessary to take into account all the clinical characteristics of the patient (hormone levels and volume of the thyroid gland, the presence of nodes, the dynamics of changes in hormones during drug treatment).

A blood test for antibodies to the TSH receptor is only necessary for patients with toxic goiter; in other cases it should not be used.

Effect of thyroid hormones

The level of thyroid hormones provides the basis for the functioning of the entire human body. Figuratively, the thyroid gland can be represented as a kind of “stoker” working, for example, in a large multidisciplinary hospital. In the departments of this hospital there are hundreds of doctors of different specialties, all of them different from each other and each doing their own important work. And in the basement of the hospital, in the boiler room, there is a fireman who throws coal into the firebox and heats the entire building. If the fireman heats the building too much, the rooms become hot, the doctors find it unbearable to work - everyone sweats, suffers from the heat, and gets nervous. If the building is poorly heated, the doctors get cold, wrap themselves in warm clothes, become lethargic and think only about how to warm up. In both cases, there can be no question of normal operation of the hospital.

In our example, the fireman is the thyroid gland, the coal is the thyroid hormones T4 and T3, the doctors are all the other hormones (sex hormones, adrenal hormones, etc.), and the hospital is the entire human body. If the functioning of the thyroid gland is disrupted, the function of all other hormones in our body is disrupted. The influence of thyroid hormones is similar to the influence of a fireman’s work - the work of the thyroid gland is invisible, but very important, since it determines a person’s entire life.

Excess hormones leads to a condition in which the thyroid hormones are elevated in a blood test (called thyrotoxicosis) - with it, a person is bothered by fever, sweating, irritability, nervousness, and sometimes hands shake. If a patient has a lot of thyroid hormones in the blood, rhythm disturbances develop and heart function deteriorates. At the same time, high thyroid hormones T4 and T3 are detected in the blood, and thyroid-stimulating hormone (TSH) is reduced. If a blood test reveals that the patient has an increase in the hormone free T4 or free T3, treatment is carried out until they are completely normalized. Sometimes taking pills is enough to cure, but in some cases more radical treatment is necessary - surgery or radioactive iodine therapy.

Lack of hormones manifested by weakness, lethargy, drowsiness, development of depression, feeling of chilliness, swelling. It’s like winter sets in in the body—everything goes to sleep. Irregularities in the menstrual cycle in women are typical, and the ability to become pregnant is reduced. In men, performance decreases and potency deteriorates. In case of hypothyroidism, it is important to determine not only hormones - antibodies to thyroid peroxidase are also an important indicator, and they must be checked during the initial examination of a patient with suspected decreased thyroid function.

Problems with hormones can significantly complicate pregnancy. Thyroid-stimulating hormone in women is included in the list of mandatory tests both when planning pregnancy and during it. Below we will dwell on this topic in more detail.

Thyroid hormones in children ensure normal brain development and nervous system generally. Therefore, TSH and T4 are hormones that should be determined during blood tests in children, especially in families where parents have an excess or deficiency of thyroid hormones.

Which thyroid hormone tests to take?

If you are prescribed a blood test for thyroid hormones, you need to know which hormones to take in order to, on the one hand, obtain enough data to make a diagnosis, and on the other hand, not to unnecessarily increase the price of the test.

If you need to donate blood for thyroid hormones for initial examination (preventive or in case of any complaints), just do a hormone test:

• thyroid stimulating hormone (TSH);
• free T4 hormone (FT4);
• free T3 hormone (FT3);
• antibodies to TPO (thyroid peroxidase).

If blood donation for hormones is carried out due to suspected thyrotoxicosis(in the presence of rapid pulse, fever, sweating, weight loss, tremors of the fingers, enlarged eyes), it is necessary to donate blood for hormones:

• free T4 hormone;
• free T3 hormone;
• antibodies to TPO;
• antibodies to TSH receptors.

If carried out treatment of hypothyroidism using thyroxine, the assessment of the patient's condition is usually carried out using only two indicators:

• Free T4 (thyroid hormone);
• TSH (thyroid stimulating hormone of the pituitary gland).

Determination of free T3 levels is usually not required in this situation. There is also no need to re-test for antibodies if they have already been tested previously. It is important to have a blood test before taking thyroxine tablets. During long-term treatment, if the dose of the drug has already been clearly established, only a blood test for TSH may be sufficient.

In patients with thyroid nodules During the first blood test you should give:

• thyroid stimulating hormone (TSH);
• free T4 hormone (FT4);
• free T3 hormone (FT3);
• antibodies to TPO (thyroid peroxidase);
• calcitonin.

If you need to decide which thyroid hormones to test during pregnancy, you should usually choose four indicators:

• free T4 hormone;
• free T3 hormone;
• antibodies to TPO.

A blood test only for TSH during pregnancy is not enough, since thyroid-stimulating hormone is low in a significant number of pregnant women, and this most often does not indicate any pathology.

After surgery to remove the thyroid gland due to the presence of papillary or follicular cancer regularly surrendered:

• free T4 hormone;
• thyroglobulin;
• antibodies to thyroglobulin.

After surgery to remove medullary cancer thyroid gland are given:

• free T4 hormone;
• calcitonin;
• CEA (carcinoembryonic antigen).

Please pay attention to some important rules that will allow you to save money when deciding which thyroid hormones to take:

1. The level of antibodies to TPO (Ab to TPO) is never re-determined; this indicator should be determined only once, since it has now been clearly proven that fluctuations in the level of antibodies are in no way related to the patient’s condition and at the level of Ab-TPO there are no recommendations for treatment are based. If a doctor asks you to donate blood again for AT to TPO, ask him what information he expects from this test, and how his actions will change depending on one or another test result.

2. Never donate total hormones T4 and T3 and free hormones T4 and T3 at the same time. If in the same blood test a doctor or laboratory employee asks you to take T4 and T4 st., or T3 and T3 st., you should know that you are being deceived in order to increase your expenses.

3. Never take a blood thyroglobulin test during the initial examination of the thyroid gland. Thyroglobulin is a specific test used only in patients with papillary thyroid cancer, and only after removal of the thyroid gland. Dishonest or insufficiently educated doctors prescribe it to patients for the same purpose - to increase the cost of examination, and the result is often the revelation that thyroglobulin is elevated - this leads patients to panic, and gives doctors the opportunity to further inflate the scope of the examination.

4. Do not test for antibodies to TSH receptors during the initial examination (except in cases where there is reasonable suspicion of thyrotoxicosis). This test is quite expensive and is only needed to treat patients with excess thyroid hormone (thyrotoxicosis).

5. Do not take the calcitonin blood test again unless you have recently developed new thyroid nodules or have had surgery for medullary thyroid cancer. In all other cases, a repeat blood test for calcitonin is another way to make money on the patient

Thyroid hormone levels.

Strictly speaking, discussing thyroid hormone levels these days is a kind of archaism, although many patients are looking for exactly this information on the Internet. Nowadays, each laboratory analyzer has its own standards, which depend on both the model of the device and the reagents used. However, in the vast majority of cases, for such an indicator as thyroid hormones, the norm is determined by international agreements, and intra-laboratory standards usually do not differ significantly from global standards. Let's take a brief look at the most important norms. Let’s just say before this that for indicators such as thyroid hormones and thyroid-stimulating hormone, the norm for women and men is no different - these hormones do not depend on the gender of the patient.

Thyroid-stimulating hormone (TSH)– a hormone, the norm of which throughout the world is about 0.4-4.0 µIU/ml. There is a separate standard for such a high-precision device as the modern 3rd generation immunochemiluminescence analyzer Abbott Architect (USA) - 0.35-4.94 µIU/ml. If your analysis indicates the norm for the TSH hormone is 0.23-3.4 µIU/ml, you should know that your analysis was performed using outdated 2nd generation enzyme immunoassay technology and cannot be completely trusted. The error in determining the TSH level for enzyme-linked immunosorbent devices is +/- 0.5 µIU/ml, while the error of a modern 3rd generation immunochemiluminescent device is +/- 0.01 µIU/ml, i.e. 500 times less!

Free T4 hormone– its norm is usually for 3rd generation devices from 9 to 19 pmol/l (there is also a norm of 9-22 pmol/l and other norms that differ slightly from the basic one).

Attention! It is important to note that a number of laboratories regularly incorrectly determine the level of free T4 hormone, underestimating its value. If your blood test shows low T4 and normal TSH at the same time, the test was done incorrectly, and you should have it redone in a better laboratory. The same should be done in a situation where the analysis reveals both normal TSH and high T4 or T3 - such an analysis also raises doubts and requires a retake in a specialized institution.

Free T3 hormone– its norm for modern immunochemiluminescent analyzers of the 3rd generation is usually 2.62-5.69 pmol/l. Free T3 hormone is one of the most difficult tests to produce, which is why the largest number of laboratory errors is associated with it. Technologically, the test for T3 St. is designed so that in some situations it can give a falsely increased value. Therefore, in cases where a questionably elevated free hormone T3 is detected, an additional test for total T3 can be prescribed - this is perhaps the only case when determination of both total and free hormone can be recommended for the same patient.

T3 hormone– is extremely important for a person, therefore its deviation from the norm occurs only in case of serious dysfunction of the thyroid gland. Unfortunately, we encounter plenty of errors in its definition. True, most often an error in the analysis can be identified purely logically, taking into account the relationships between hormones, which are almost never disrupted.

A repeat blood test for thyroid hormones in a specialized 3rd generation laboratory is required in the following cases: - T3 hormone is increased, TSH is normal; - T3 hormone is decreased, TSH is normal; - T3 hormone is decreased, T4 is normal.

Calcitonin– its norm in different laboratories can vary quite significantly. It is important to remember one rule: any increase in blood calcitonin levels requires contacting a specialized endocrinology center. In our practice, there have been cases of detection of medullary cancer with a diameter of 3 mm in situations where blood calcitonin was increased by 0.5 units from upper limit norms. In all doubtful cases, when the calcitonin hormone is slightly elevated, specialists from the endocrinology center conduct a stimulated test for calcitonin with intravenous administration 10% calcium gluconate - this test allows you to clearly understand the situation and make the correct diagnosis. A stimulated test for blood calcitonin is carried out only in specialized institutions.

Antibodies to TPO– their norm varies especially greatly between different laboratories. There are standards from 0 to 20 IU/l, and standards from 0 to 120 IU/l, and other variants of standards. That is why you definitely don’t need to memorize them - the analysis form will indicate the standard for your laboratory, and you should use it. It is important to understand only a few features of the test for antibodies to TPO:

1. How elevated the antibodies to TPO are from the upper limit of normal is not important. If the upper limit of the norm is, for example, 4.11, and your result is 2000, do not be alarmed. Oddly enough, scientific research has shown that it is the fact of an increase in TPO antibodies that is important, and not the degree of their increase.
2. The level of antibodies to TPO cannot be “good” or “bad”. If the antibody norm is indicated in the range from zero to 120, and your result is 118, this does not mean that your result is worse than, say, 15. The norm is the norm, therefore any indicator of antibodies to TPO that falls within the norm should be considered normal. No matter how obvious this fact is, very often patients come to us who are frightened by the result of antibodies to TPO, which is near the upper limit of the norm - and, of course, their fears are completely unfounded.

Antibodies to thyroglobulin– their norm in specialized immunochemiluminescence laboratories of the 3rd generation usually ranges from 0 to 4.11 IU/l, or from 0 to 65 IU/l. Antithyroglobulin antibodies are elevated in patients with autoimmune diseases(for example, with autoimmune thyroiditis). Antithyroglobulin antibodies are also often elevated in patients with papillary thyroid cancer - for reasons that are not yet entirely clear in this group of patients elevated antibodies occur in 25-30% of cases.

For patients testing antithyroglobulin antibodies after surgery to remove the thyroid gland for papillary cancer, it is important to know that the results of the anti-TG antibody test performed in different laboratories cannot be compared with each other. If in one laboratory the norm of antibodies to thyroglobulin is from zero to 4, and your indicator is 8, this does not mean that for a laboratory with a norm from zero to 100, your indicator will be 200. Unfortunately, recalculation of results between different laboratories is absolutely not possible available. An important rule follows from this fact: a blood test for antibodies to thyroglobulin should be taken in the same laboratory. Of course, it is desirable that this laboratory be specialized and based on the use of 3rd generation equipment.

If you have done tests and want to have an express consultation with a specialist on the Internet for 100-200-300 (whatever you don’t mind) rubles or for free, then write in the comments, I will give you the coordinates

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