was kann man im blut alles feststellen — what are common causes?

Blood tests can detect a wide range of parameters that provide insight into health status. Common measurements include lipids (cholesterol, triglycerides), glucose and HbA1c, liver and kidney function markers, electrolytes, complete blood count (RBC, WBC, platelets), inflammatory markers (CRP), and hormones (thyroid, sex hormones). Genetic testing from blood is also possible, e.g., single SNPs like rs10830963 in MTNR1B (fasting glucose) or pharmacogenetic variants like SLCO1B1 (statin myopathy risk). Common causes of abnormal results include diet, lifestyle, genetic predisposition, medications, infections, and chronic diseases. Caveat: a single SNP or biomarker is rarely deterministic. Evidence ranges from strong (e.g., SLCO1B1-simvastatin myopathy) to unclear (e.g., antioxidant SNPs). Blood tests are screening tools, not definitive diagnoses. Always consult a physician for abnormal results.