was ist tsh wert — what does this mean exactly?

TSH (thyroid-stimulating hormone) is produced by the pituitary gland and controls the thyroid. A single TSH value gives a first indication of whether the thyroid is functioning normally, overactive, or underactive. However, one measurement alone is not diagnostic – TSH fluctuates throughout the day and is influenced by stress, sleep, medications, and even season. For a full assessment, free T3, free T4, and possibly antibodies (TPO-Ab, Tg-Ab) plus ultrasound are needed. Most labs report a reference range of about 0.4–4.0 mU/l, but individual optimal levels may differ. TSH below 0.4 may suggest hyperthyroidism; above 4.0 may suggest hypothyroidism – but subclinical forms exist. If your value is abnormal, a doctor should interpret it in context. Self-testing without medical guidance can lead to misinterpretation or unnecessary worry. The evidence is based on clinical practice and guidelines, not on a single genetic or home test.