wie lange vor blutabnahme nichts trinken — what can you do yourself?

The standard recommendation before a blood draw, especially for fasting values like blood glucose and lipids, is: nothing to eat for 8–12 hours, and only water is allowed. Coffee, tea (even unsweetened), juice, milk, or alcohol can skew results. Smoking should also be avoided. What you can do yourself: schedule the appointment in the morning so the fasting period falls overnight. Drink a glass of water beforehand – it helps with vein access and prevents dizziness. For some tests (e.g., complete blood count, thyroid hormones) fasting is not strictly required; ask your doctor if unsure. Important: if you have diabetes or other metabolic conditions, do not extend the fasting period without medical advice. The evidence for these guidelines is strong (human-strong), based on decades of clinical practice and guidelines. No DNA tests or personalized approaches are needed – the general recommendations apply to everyone.