Start from here
TSH catches subclinical stages, when T4 is still normal, but metabolism is already suffering; on L-thyroxine therapy, the dose is titrated according to TSH (control 6–8 weeks after the change). For pregnant women and those planning to take it, it is a must: even mild hypothyroidism of the mother affects the development of the child. Deviations are complemented by free T4 and antibodies.
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.