was kann man im blut alles feststellen — what can you do yourself?

With a home blood test you can measure various biomarkers such as vitamin D levels, thyroid parameters (TSH, fT3, fT4), inflammation markers (CRP), blood lipids (cholesterol, triglycerides), or allergies (IgE antibodies). Cortisol day profiles or nutrient deficiencies (iron, B12, magnesium) are also possible. Sampling is usually done via capillary blood from a fingertip. Important: These tests provide snapshots, not diagnoses. They can indicate tendencies but cannot distinguish between disease and normal variation. For serious symptoms (e.g., persistent stomach aches, fatigue, joint pain) a doctor visit is essential. Many self-tests lack clinical validation, especially for children. The reliability depends heavily on lab quality and interpretation. A DNA test (e.g., MyBody-X) shows genetic predispositions, not current blood values. Bottom line: Self-tests can serve as orientation but do not replace medical evaluation. If you have specific complaints, always consult a physician.