When is it prescribed?
The niche of the test is continuity of observation and separate protocols for monitoring thyreostatic therapy. For primary diagnosis, free fractions are preferred; There is no point in switching between “common” and “free” in dynamics - the curves are incomparable.
When is it appointed?
- fatigue, weight gain/loss, palpitations, hair loss - TSH screening;
- thyroid nodules - hormones + calcitonin;
- control of therapy with L-thyroxine and thyreostatics;
- pregnancy planning and pregnancy - mandatory TSH;
- autoimmune thyroiditis - antibodies.
Logic of thyroid tests
TSH is the main regulator and the most sensitive screening: the pituitary gland responds to the slightest changes in gland hormones. Free T4 and T3 clarify the severity of hypo-/hyperthyroidism, antibodies (AT-TPO, AT-TG) find an autoimmune cause, antibodies to TSH receptors confirm Graves' disease, calcitonin protects against medullary cancer in the nodes. Always start with TSH - the rest is according to indications, without unnecessary expenses.