Evidence check: Testosteron Test in the context of Müdigkeit

Testosterone testing for fatigue is a common offering, but the evidence is mixed. Low testosterone can contribute to fatigue, low energy, and reduced libido, especially in older men. However, fatigue is a non-specific symptom with many potential causes (e.g., sleep deprivation, stress, thyroid dysfunction, iron deficiency, depression). Most studies indicate that testosterone deficiency is only a minor factor in general fatigue. Reference ranges vary, and a single measurement is unreliable. The Endocrine Society recommends testing only when clinical signs are present and with repeated morning samples. Without medical context, a testosterone test may lead to misinterpretation or unnecessary supplementation. Evidence grade: practice/mixed. Sources: none from provided context.