Analysis for thyroid hormones

Thyroid hormones biologically highly active substances produced in thyroid and pituitary gland to regulate the metabolic processes of fat, protein and carbohydrates, the function of the cardiovascular system and gastrointestinal tract, sexual and mental activity.

What does a blood test for thyroid hormones?

Increase or decrease in production of triiodothyronine, thyroxine and thyroid-stimulating hormone is thyroid dysfunction.

  • Hyperthyroidism (thyrotoxicosis) — a condition associated with increased production of thyroid hormones;
  • Hypothyroidism — a condition associated with decreased production of thyroid hormones.

What are the indications for the purpose of analysis for thyroid hormones?

  1. detection of hypothyroidism and hyperthyroidism;
  2. control study in hypothyroidism, diffuse toxic goiter;
  3. mental retardation and sexual development in children;
  4. goiter;
  5. cardiac arrhythmias;
  6. alopecia (hair loss);
  7. infertility;
  8. amenorrhea (absence of menstruation);
  9. impotence and decreased libido.

What indicators are included in the analysis of blood for thyroid hormones?

1) TSH (thyroid-stimulating hormone, thyrotropin) — pituitary hormone that stimulates the formation and secretion of thyroid hormones (T3 and T4). In normal pituitary function, its concentration decreases with increasing and at a decrease in thyroid function.

Normal values: 0.4-4.0 mU / l.

2) Free T3 (triyodtironin free)— thyroid hormone, which stimulates the metabolism and absorption of oxygen by tissues.

Normal Values: 2.6 — 5.7 pmol / l.

4) Free T4 (free thyroxine)thyroid hormone, which stimulates the synthesis of proteins.

Normal Values: 9.0 — 22.0 pmol / l.

5) Antibodies to thyroglobulin (TG-AT) — antibodies to the protein precursor of thyroid hormones are an important parameter for the detection of autoimmune thyroid diseases such as Hashimoto's disease, autoimmune atrophic thyroiditis, Graves' disease.

Normal Values: 0 — 18 U / ml

6) Antibodies to thyroid peroxidase (TPO, microsomal antibodies) — autoantibodies to the enzyme thyroid cells, the most sensitive test for the detection of autoimmune thyroid disease.

Normal values: <5.6 U / ml.

How to prepare for the study? 

  • A month before the study is necessary to exclude admission of thyroid hormones, unless otherwise directed by a physician, endocrinologist.
  • 2-3 days stop taking drugs containing iodine.
  • On the eve of research is needed to exclude physical activity (sports training), stress, alcohol and smoking.
  • Blood collection should be carried out prior to the studies using contrast media. Blood is taken on an empty stomach. Immediately before taking blood patient should be at rest for about 30 minutes.

What is the period of performance analysis?

1 day.

How to interpret the tests for thyroid hormones?

Normal concentrations of hormones in the blood may be slightly different depending on the laboratory method, gender and age of the patient, so the doctor-endocrinologist should focus on the reference values specified in the blank lab.

What do the changes in a blood test for thyroid hormones?



Free T3

4 free




Primary hypothyroidism

Decreased or OK

Decreased or OK




Hypothyroidism secondary












Hashimoto's thyroiditis or subacute

Perhaps a combination of thyroiditis with hypothyroidism or hyperthyroidism.



SQL - 16 | 0,431 сек. | 6.93 МБ