was ist tsh wert — what are common causes?

TSH (thyroid-stimulating hormone) is a pituitary hormone that regulates thyroid function. Common causes of abnormal TSH levels include: **Elevated TSH** – primary hypothyroidism (Hashimoto's, iodine deficiency), subclinical hypothyroidism, pituitary TSH-secreting tumors (rare), or medications like lithium. **Low TSH** – hyperthyroidism (Graves' disease, toxic nodules), excessive thyroid hormone replacement, or secondary hypothyroidism (pituitary failure). Non-thyroidal illness, stress, and certain drugs (dopamine, glucocorticoids) can also suppress TSH. Interpretation requires free T3/T4, age-specific reference ranges, and clinical context. A single TSH value is insufficient for diagnosis. The evidence for these associations is strong in medical literature (human-strong), but the provided context does not contain specific sources. Therefore, evidence is marked as 'unclear' due to lack of direct references in the given material.