Questions people ask about TSH Labor

TSH (thyroid-stimulating hormone) is a key lab value for assessing thyroid function. Common questions revolve around the reference range: it varies by lab, age, sex, and pregnancy – typically 0.4–4.0 mU/L, but newer guidelines often suggest narrower limits (e.g., 0.5–2.5 mU/L). Elevated TSH indicates primary hypothyroidism; low TSH suggests hyperthyroidism or central dysfunction. Importantly, TSH alone is insufficient – it should be interpreted with free T3, free T4, thyroid antibodies (TPO, Tg), and possibly ultrasound. Factors like medications (biotin, glucocorticoids), time of day (TSH peaks in the morning), and non-thyroidal illness (e.g., renal failure) can alter TSH. Borderline values (subclinical hypo-/hyperthyroidism) require individualized clinical judgment. TSH testing is a screening tool, not a standalone diagnosis. Evidence is strong (human-strong), but interpretation requires medical expertise. MyBody-X does not offer TSH testing; this is a standard clinical lab parameter.