Blood test for hormones, norm and interpretation of indicator results

When is a blood test for hormones prescribed?

Hormonal analysis is usually carried out if there is a suspicion of dysfunction of the endocrine glands or if an increase in the size of the glands is detected.

Indications for testing for female sex hormones (estrogens)

are:

• menstrual irregularities;
• infertility;
• miscarriage;
• acne;
• overweight;
• fibrocystic mastopathy (breast disease).

Indications for testing for male sex hormones (androgens)

are:

• suspicion of the development of tumor processes;
• ovarian dysfunction;
• kidney dysfunction;
• overweight (obesity);
• infertility;
• acne;
• in women – excessive growth of body hair.

Hormonal analysis is prescribed during pregnancy if pathological development of the fetus is suspected. An analysis for the hormone hCG (human chorionic gonadotropin), produced by the cells of the membrane of the embryo, can detect pregnancy already on the 6-10th day after fertilization.

General definition

A blood test for hormones can reveal whether hormonal balance is disturbed. Today there is an increase in endocrine diseases caused by dysfunction of the endocrine glands. To prevent negative consequences by starting therapy in a timely manner, it is recommended to regularly check your hormonal levels. This can be done in our multidisciplinary medical. Highly qualified specialists who have the best diagnostic equipment at their disposal will help identify problems in the body’s functioning at the earliest stages.

Blood test for hormones when planning pregnancy

It is very important to take a blood test for hormones when planning a pregnancy. Timely assessment of hormonal levels will help avoid possible problems.

The main hormones that are checked when planning pregnancy:

• FSH (follicle-stimulating hormone)
  - in women, is responsible for the growth of the egg (follicle) in the ovary. In men, it is one of the main sex hormones that regulate reproductive function.
• LH (luteinizing hormone)
  - in women, ensures completion of the maturation of the egg in the follicle and subsequent ovulation (rupture of the follicle and release of the egg). In men, it affects the maturation of sperm.
• Prolactin
  – stimulates lactation after childbirth. During pregnancy, it reduces the release of FSH. If there is no pregnancy, an increased amount of prolactin can lead to a pathological deficiency of FSH and prevent conception.
• Estradiol
  - affects all female genital organs.
• Progesterone (pregnancy hormone)
  is produced after the egg matures. Without this hormone, a fertilized egg cannot attach to the uterus. Lack of progesterone can cause miscarriage.
• Testosterone
  is a male sex hormone; an increased amount of testosterone in women can lead to miscarriage, and a decreased amount in men can lead to decreased sperm quality.
• DEA sulfate
  (DEA-s or DEAS) is produced in small quantities in the body of women. Increased concentrations of this hormone can lead to infertility.
• Thyroid hormones.
  Thyroid dysfunction can also cause infertility.

Decreased free T3

The lack of free T3 in the body may be due to the following factors:

• hypofunction (insufficiency) of the thyroid gland;
• hypothyroidism (critically low production of endocrine hormones);
• thyroiditis (subacute, acute form);
• adrenal insufficiency;
• severe systemic diseases, recent surgeries or injuries;
• serious eating disorders (fasting, low-calorie diets or low protein content in the daily diet);
• sudden weight loss, anorexia, etc.

The test results are interpreted by an endocrinologist, general practitioner or therapist.

How to donate blood for hormones. Interpretation of analysis results.

Blood from a vein is used to test hormones.

Depending on the clinical signs indicating a specific pathology, an analysis with tests for specific hormones is usually prescribed.

The most complete picture of your health can be obtained by taking a test for the following hormones.

Thyroid hormones:

• T3 (triiodothyronine)
  free – stimulates oxygen metabolism in tissues. Normal values: 2.6 - 5.7 pmol/l.
• T4 (thyroxine)
  – stimulates protein synthesis. Normal values: 0.7-1.48 ng/dl.
• Antibodies to thyroglobulin (AT-TG)
  are an important parameter for identifying a number of autoimmune diseases. Normal values: 0-4.11 U/ml.
• Some others
  .

Pituitary hormones:

• TSH (thyroid-stimulating hormone)
  – stimulates the production of thyroid hormones (T3 and T4). Normal values: 0.4-4.0 mU/l. An elevated TSH value usually indicates decreased thyroid function.
• FSH (follicle stimulating hormone)
  . Normal values: in women - depends on the phase of the menstrual cycle. Phase I – 3.35-21.63 mU/ml; Phase II – 1.11-13.99 mU/ml; postmenopause – 2.58-150.53 mU/ml; girls under 9 years old 0.2-4.2 mU/ml. In men – 1.37-13.58 mU/ml.
• LH (luteinizing hormone)
  . Normal values: in women - depends on the phase of the menstrual cycle. Phase I – 2.57-26.53 mU/ml; Phase II – 0.67-23.57 mU/ml; postmenopause – 11.3-40 mU/ml; girls under 9 years old - 0.03-3.9 mU/ml. In men – 1.26-10.05 mU/ml.
• Prolactin
  .
  The main function is to stimulate the development of mammary glands and lactation. Normal values: in women (from the first menstruation to menopause) – 1.2-29.93 ng/ml; in men – 2.58-18.12 ng/ml. Increased concentrations of prolactin are called hyperprolactinemia
  . There are physiological and pathological hyperprolactinemia. Physiological hyperprolactinemia can be caused by breastfeeding, pregnancy, severe physical activity, and stress. An increased concentration of prolactin in women leads to menstrual irregularities and may cause infertility. In men, hyperprolactinemia leads to decreased libido and impotence.
• ACTH (adrenocorticotropic hormone)
  – stimulates the synthesis and secretion of hormones from the adrenal cortex. Normal values: 9-52 pg/ml.
• Some others
  .

Sex hormones:

• Testosterone
  (male sex hormone) is produced by the adrenal glands and in the gonads (in men - in the testicles, in women - in the ovaries). Affects the development of the genital organs, the formation of secondary sexual characteristics, the growth of bones and muscles. Normal values: for men - 4.94-32.01 nmol/l, for women - 0.38-1.97 nmol/l.
• Estrogens
  (female sex hormones). The main estrogens - progesterone and estradiol - are produced by the adrenal glands and ovaries. Normal values ​​of progesterone in women depend on the phase of the menstrual cycle: Phase I – 1.0-2.2 nM/l; Phase II - 23.0-30.0 nM/l; for postmenopause – 1.0-1.8 nM/l. Similarly for estradiol: phase I - 198-284 pM/l: phase II - 439-570 pM/l; for postmenopause – 51-133 pM/l. Elevated estrogen levels may indicate tumors of the ovaries and adrenal cortex, as well as cirrhosis of the liver. Reduced - for insufficient development and sclerosis of the ovaries.

Adrenal hormones:

• DEA-s (dehydroepiandrosterone sulfate)
  is necessary for the synthesis of testosterone and estrogens. The normal range for the concentration of this hormone is: 3591-11907 nmol/l; in women – 810-8991 nmol/l. However, this is the general picture; when processing analysis data, the patient’s age must also be taken into account.
• Cortisol
  is involved in many metabolic processes and is actively produced as a result of the body’s response to hunger or stress. Normal values: for children under 16 years of age - 3-21 mcg/dl, for an adult - 3.7-19.4 mcg/dl.
• Aldosterone
  is responsible for regulating water-salt balance in the body. Normal values: 35 - 350 pg/ml.

What is free triiodothyronine (FT3)?

The thyroid gland is located in the neck, in which metabolic processes in the body are regulated through the production of free triiodothyronine (FT3) and thyroxine (FT4).
Free triiodothyronine is produced by the follicular cells of the thyroid gland under the control of thyroid-stimulating hormone. In peripheral tissues it is formed during the deiodination of free thyroxine (T4). Free triiodothyronine is the active part of total triiodothyronine. Triiodothyronine is more active than thyroxine, but is found in the blood in lower concentrations. Free form means that it is not bound to plasma proteins. The functions of free trioidthyronine also include:

• an increase in heat production and oxygen consumption by all tissues of the body, with the exception of the tissues of the brain, spleen and testicles;
• stimulation of vitamin A synthesis in the liver;
• reducing the concentration of cholesterol and triglycerides in the blood;
• acceleration of protein metabolism;
• increased urinary calcium excretion;
• activation of bone tissue turnover;
• having a positive chrono- and inotropic effect on the heart;
• stimulation of cortical processes in the central nervous system.

Preparing for a hormone test

The amount of hormones in the blood depends on the time of day, since there is a daily rhythm of secretion (release of hormones). Blood for hormonal analysis should be taken in the morning, on an empty stomach.

In women, hormonal levels also depend on the stage of the menstrual cycle. The most favorable days for analysis are days 5-7 of the cycle, starting from the first day of menstruation.

On the eve of the test, you should not drink alcohol, and you should also avoid increased physical activity and stressful situations. It is advisable not to smoke for an hour before the test.

A week before the test, you must stop taking hormonal medications. If you are prescribed medication, discuss this with your doctor; the test may have to be postponed.

Free T3 norm

For female patients, the T3 norm is lower than for males (by approximately 5-10%). During pregnancy, the hormone level drops even more and is restored only a week after birth.

The indicator is different for children and adults (the constant level of the hormone stabilizes by 12-15 years). After 65 years, its concentration decreases noticeably.

Reference values ​​for free T3

The results of the study may be affected by:

• loads, stress, sports training;
• violation of the prescribed diet on the eve of the procedure;
• consumption of alcohol and drugs;
• taking medications: hormones (including oral contraceptives), dexamethasone, salicylates, amiodarone, coumarin derivatives, lithium and iodine preparations;
• season of the year (in the autumn-winter period T3 indicators peak, and by summer they reach the minimum acceptable values).

References

1. Hypothyroidism. Clinical recommendations. Association of Endocrinologists of Russia, 2021. - 38 p.
2. Federal clinical guidelines for the diagnosis and treatment of thyrotoxicosis with diffuse goiter (diffuse toxic goiter, Graves-Bazedow disease), nodular/multinodular goiter, 2014. - 45 p.
3. Encyclopedia of clinical laboratory tests / ed. WELL. Titsa. - M.: Labinform, 1997. - P. 461-465.
4. Kumar, V., Abbas, A., Fausto, N. et al. Robbins and Cotran Pathologic Basis of Disease, 2014. - 1464 p.