Thyroid-Stimulating Hormone (TSH)

Analyte [material]

Thyroid-stimulating hormone (TSH) [S/P]

Reference range, target level, or decision threshold

0.4-4.0 mIU/L (depending on the method)CW !

Reference ranges in particular trimesters of pregnancy: as provided by the laboratoryCW !

Do not routinely measure TSH in asymptomatic patients.

Interpretation of results

↑ Primary (including subclinical) hypothyroidism (eg, Hashimoto thyroiditis), secondary hyperthyroidism, TSH resistance, malabsorption of thyroxine, drugs (amiodarone, lithium, tyrosine kinase inhibitors, antithyroid drugs), iodine deficiency or excess, thyroid infiltration (tumor, amyloid), congenital hypothyroidism, Riedel thyroiditis, neck irradiation, after radioiodine therapy, after thyroidectomy, hypothyroid phase of thyroiditis; TSH results may be ↑ in patients with macro-TSH

↓ Primary (including subclinical) hyperthyroidism (eg, Graves disease), secondary hypothyroidism (caused by pituitary and/or hypothalamic insufficiency), drugs (glucocorticoids, dopamine, amiodarone), toxic multinodular goiter, toxic adenoma, thyroiditis (postviral, postpartum), excess iodine intake, congenital hyperthyroidism, pregnancy-related conditions (hydatidiform mole, hyperemesis gravidarum), triiodothyronine (T3) thyrotoxicosis