welche werte bei schilddrüsenunterfunktion — what are common causes?

The question about thyroid lab values in hypothyroidism is well-established in clinical medicine, but the provided context does not contain specific thyroid data. Typical findings: elevated TSH (most sensitive marker), low free T4 (fT4), and in overt hypothyroidism also low free T3 (fT3). Common causes include: Hashimoto's thyroiditis (autoimmune, most common in iodine-sufficient regions), iodine deficiency (still prevalent in some areas), iatrogenic (post-surgery or radioiodine), medications (lithium, amiodarone), and rare congenital disorders. Diagnosis requires a physician because reference ranges vary by age, pregnancy, and comorbidities. Caveat: direct-to-consumer thyroid tests often lack clinical validation and may mislead; professional evaluation is essential.