How are TSH Schilddrüse and Müdigkeit related?

TSH (thyroid-stimulating hormone) is the master regulator of thyroid function. Elevated TSH indicates hypothyroidism (underactive thyroid), where insufficient thyroid hormones are produced. Fatigue is one of the most common symptoms of hypothyroidism, as the slowed metabolism impairs energy production. Conversely, hyperthyroidism (low TSH) can also cause fatigue, often due to sleep disturbances and overall metabolic stress. The evidence for this relationship is clinically strong (numerous studies, guidelines). However, a single TSH value is not diagnostic; it must be interpreted alongside fT3, fT4, symptoms, and possibly antibodies. Fatigue has many causes (iron deficiency, sleep apnea, depression, vitamin D deficiency), so medical evaluation is essential. The provided context contains no specific sources on TSH and fatigue; this answer is based on established medical knowledge.