THS is a hormone of the anterior pituitary gland (a gland in the brain) which regulates the amount of T3, T4 hormones produced by the thyroid gland. “Ultrasensitive” means that the analysis is performed by electrochemiluminescence (ECL), which is 2 orders of magnitude more than the RIA method and 1 order of magnitude more than the IFA. ECL makes it possible to determine a TSH concentration of less than 0.01 mEU/L, which makes it possible to distinguish between borderline states of normal and reduced amounts of the hormone.

The regulation of TSH production is based on the feedback principle. If the thyroid gland cannot produce the right amount of hormone (for example, due to iodine deficiency), the pituitary gland receives a signal that the thyroid is failing. Then the pituitary gland increases the TSH production, which stimulates the thyroid gland to absorb iodine and “force” it to produce more T3, T4.

The concentration of TSH is characterized by daily fluctuations: the maximum value is diagnosed at 2-4 a.m., then the level goes down and reaches a minimum by 5-6 p.m.

The analysis is necessary to diagnose thyroid dysfunction (hypo-, hyper-thyroidism), as well as to select the correct dose of hormone medication.