Thyroid-stimulating hormone: normal and abnormalities

What is thyroid-stimulating hormone?

The thyroid gland has right and left lobes connected by an isthmus that looks like a butterfly. The main function of this gland is to synthesize free T3 (triiodothyronine) and free T4 (thyroxine). Its activity is regulated by the pineal gland, pituitary gland, and hypothalamus. And the main regulator is TSH (thyroid-stimulating hormone). Let's look at what it is responsible for, how it affects the thyroid gland and the entire body.

What is TSH and how does it affect the thyroid gland?

As already mentioned, TSH is the main regulator for the functions performed by the thyroid gland. 

When the thyroid-stimulating hormone is above normal, it enters the bloodstream in increased amounts. In turn, this causes hyperthyroidism. 

Its symptoms are as follows: 



-significant irritability 

-noticeable weight loss; 

-generalized weakness; 

-increased fatigue; 


-deterioration of vision 

-swelling of the eyelids; 


If the thyroid-stimulating hormone is reduced, it leads to hypothyroidism. Its key symptoms are:

-menstrual irregularities;

-unexplained swelling;

-significant bradycardia; 

-dryness (noticeable) of the skin; 

-significant weakness.

-Patients also experience hair loss, memory loss, etc.

The test is recommended before 6 am on an empty stomach. It has been proven that the concentration of the hormone is highest from two in the morning until six. During the examination period, you should avoid physical and emotional stress.

What functions does thyroid-stimulating hormone perform in the body?

By acting on certain receptors in the thyroid gland, TSH can stimulate the activation and overall production of thyroxine. 

The subsequent increase in cAMP levels causes TSH to affect the biosynthesis of T3 (triiodothyronine) and T4 (thyroxine). These growth hormones are extremely important for humans. Also, TSH causes some known long-lasting effects. For example, when thyroid-stimulating hormone is elevated, we can talk about a significant increase in the synthesis of protein, nucleic acid group, phospholipid, as well as changes in the size and number of thyroid cells. 

How to get tested for thyroid-stimulating hormone?

The material for the test is blood serum taken from a vein. For the most accurate result, you should:

For 2-3 days, exclude physical and emotional stress, smoking, alcohol, fatty or spicy foods. 

After eating, the break should be about 9-10 hours. 

Women should have the test done 5 days before menstruation or after 5 days of menstruation. 

Smoking is not allowed at least 60 minutes before the test.

Those who take thyroid drugs should skip them in the morning before the test. 

What are the TSH norms for different age groups and genders?

The main indicators of the norm for people of different genders and ages are given below:

-Normally, TSH in women can be 0.3 - 4.2 μIU/ml. 

-Its concentration in pregnant women may vary and be 0.2-3.5 µIU/ml. 

-In men, the normal thyroid-stimulating hormone level is 0.4-4.0.

-For newborns, the norm is 1.1-17.0.

-In children under 2.5 months, the norm is 0.6-10.0.

-Subsequently, by 14 months, the normal value is already 0.4-7.0.

-In even older children under 5 years of age - 0.4-6.0.

-For adolescents under 14 years old, the normal range is 0.4-5.0.

-From the age of 14, the norm is 0.4-4.0.

So, TSH norms depend on gender and age. The indicator changes dramatically due to hormonal changes in the body in adolescents. The results of the analysis will show the level at which the antibodies to TSH are present, and the TSH high-sensitivity biotin-independent will be indicated. Therefore, it will be possible to draw conclusions about thyroid disorders (online consultation - find out your TSH value).

What signs indicate an increase in TSH levels?

Elevated TSH (hyperthyroidism) may be indicated by



-unexplained fussiness

-problems with sleep;

-heartbeat at a rapid pace;

-weight loss without objective reasons.

-Suspicion of hypothyroidism (low TSH) may be caused by the following symptoms

weakness and shortness of breath;

-increased fatigue;

-weight gain;

-depressive states;

-low blood pressure;


-nausea, swelling, regular constipation;

-noticeably deteriorated condition of the skin, hair, nails, hair, skin.

TSH levels may be recommended by surgeons, gynecologists, endocrinologists, pediatricians, etc.

What causes can lead to an increase in thyroid-stimulating hormone?

The following conditions can lead to an increase in TSH:

-Primary hypothyroidism.

-Iodine deficiency.

-Pathologies and problems of the thyroid gland.

-Adrenal insufficiency.

-Pre-eclampsia (against the background of a condition when a woman's blood pressure was normal until the 20th week of pregnancy, and then hypertension began).

-Pituitary tumor.

-History of thyroidectomy.

-Autoimmune or Hashimoto's thyroiditis (found in only 3% of the world's population).

-Neoplasms secreting thyrotropin.

-Significant decrease in T4 and T3 sensitivity.

-Certain mental illnesses.

-Poisoning (of varying severity) with lead.

TSH can often be elevated after long-term somatic diseases during recovery.

How to treat thyroid-stimulating hormone if it is elevated?

In most patients with moderately elevated TSH levels (approximately 10 mIU/L), the values normalize without treatment or intervention. 

To make sure that the body is "acting correctly," an additional TSH test should be performed in 1.5-2 months to determine the TSH and free T4 levels. If abnormalities are detected again, treatment may be recommended. Because if the thyroid-stimulating hormone is elevated, there is no definite answer. 

What symptoms indicate TSH deficiency?

The main signs of hypothyroidism are

1)a feeling of stable cold;

2)increased fatigue, significant drowsiness;

3)regular depression;

4)memory problems;

5)weight gain;


7)low blood pressure, slow heart rate;

8)pale, flaky, dry skin, dry hair;

9)problems in the menstrual cycle, infertility.

Studies may reveal anemia and a significant increase in cholesterol levels. The severity may be barely noticeable or not at all, and can be quite severe. The consequences (depending on the severity) include heart disease, infertility, and sometimes coma.

What factors can cause a decrease in thyroid-stimulating hormone?

Below normal TSH levels can be triggered by a number of factors:

-Various thyroid problems.

-Autoimmune thyroiditis.

-Plummer's disease or toxic adenomas.

-Functional extinction of the hypothalamus and/or pituitary gland.

-Cerebral stroke and head injuries.

-Hypocortisolism and infections.

-Cachexia and certain medications.

Physical (increased) activity, various forms and severity of stress, a long-term fasting plan, or a severe diet can also cause a decrease in TSH concentration.

How to raise TSH levels if they are low?

Hypothyroidism is treated by systematically replacing the hormones that the thyroid should produce. For example, levothyroxine is popular. It is synthetic, but identical to the hormone that the thyroid normally produces, and has the same effect. 

Can hypothyroidism be completely cured? Sometimes this disease even disappears on its own, that is, without treatment. But in most cases, TSH control and levothyroxine are required for life.


Q: What are the functions of thyroid-stimulating hormone in the human body?

A: The key function is to maintain stable hormonal levels. If the TSH level in the blood decreases, the hypothalamus releases the hormone, which, thanks to the pituitary gland, stimulates the secretion of TSH by the pituitary gland. 

Q: What are the causes and symptoms of abnormal blood levels of thyroid-stimulating hormone?

A: Primary hypothyroidism, iodine deficiency, thyroid pathologies and problems,

adrenal insufficiency, pre-eclampsia (against the background of a condition when a woman's blood pressure was normal until the 20th week of pregnancy, and then hypertension began), pituitary tumor, thyroidectomy in history, autoimmune or Hashimoto's thyroiditis, thyrotropin-secreting neoplasms, a significant decrease in T4 and T3 sensitivity, certain mental illnesses, and lead poisoning (of varying severity).

Q: How to take a blood test for thyroid-stimulating hormone and how to interpret the results?

A: For the most accurate result, it is necessary to exclude physical and emotional stress, smoking, alcohol, fatty or spicy foods for 2-3 days. It is also undesirable to overheat or overcool. Women should take the test 5 days before menstruation, or after 5 days of menstruation.

Опубліковано: 18.12.2023 2402

Фурманова Оксана Іванівна

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