Evidence check: TSH Schilddrüse in the context of fatigue

TSH (thyroid-stimulating hormone) is a well-established biomarker for thyroid function. Hypothyroidism can cause fatigue, and TSH testing is commonly used in clinical settings to evaluate fatigue. However, the evidence for using TSH alone in consumer DNA or home lab tests for fatigue is mixed. Fatigue has many causes (e.g., sleep deprivation, stress, iron deficiency, depression), and a normal TSH does not rule out other etiologies. Moreover, TSH levels can fluctuate due to time of day, diet, or medications. Clinical guidelines (e.g., USPSTF) do not recommend routine TSH screening in asymptomatic individuals. For fatigue with suspected thyroid dysfunction, a full thyroid panel (TSH, fT3, fT4, antibodies) under medical supervision is more appropriate. A standalone consumer TSH test may provide false reassurance or unnecessary concern. Conclusion: TSH is relevant but insufficient for fatigue assessment; evidence for consumer testing is mixed.