wie kann man cortisol messen — when to see a doctor?

Cortisol can be measured via blood, saliva, urine, or hair samples. Blood and saliva tests reflect current levels, while 24-hour urine or hair analysis provide an average over time. You should see a doctor if you experience persistent symptoms such as unexplained fatigue, weight changes, sleep disturbances, high blood pressure, or mood swings – especially if Cushing's syndrome (excess cortisol) or adrenal insufficiency (low cortisol) is suspected. The provided context does not contain any specific information on cortisol measurement or when to consult a physician. Therefore, this answer is based on general medical knowledge. Caveat: Over-the-counter self-tests are often unreliable; clinical diagnosis should always be performed by a specialist. Evidence level: practice, not derived from the given context.