welche blutwerte bei erschöpfung und müdigkeit — which blood markers matter?

For exhaustion and fatigue, common blood markers include iron/ferritin, vitamin B12, vitamin D, TSH (thyroid), complete blood count (CBC), and CRP (inflammation). These tests can identify deficiencies or dysfunctions that may contribute to fatigue. However, evidence for routine screening in unexplained fatigue is mixed: many people with low levels are asymptomatic, and many with fatigue have normal levels. Supplementation only helps if a true deficiency exists. Important: fatigue can signal serious conditions (e.g., anemia, hypothyroidism, depression) – a medical consultation is essential. Genetic tests for nutrition or metabolism have limited value here because they do not measure current blood levels. Overall evidence for these markers is moderate (clinical practice, but not always supported by large RCTs).