Risks and limits of Cortisol Alltag

Measuring cortisol in daily life (e.g., saliva, blood, urine) is a useful tool to assess stress responses and circadian rhythms, but it has clear limitations. Single measurements are highly context-dependent (time of day, sleep, food intake, acute stress) and can easily be falsely elevated or suppressed. Repeated sampling at fixed times (e.g., morning and evening) provides more reliable data. Reference ranges vary by method and lab; an isolated abnormal value is not diagnostic. Genetic factors (e.g., COMT variants) influence cortisol breakdown, but effect sizes are small. The main risks are overinterpretation: laypeople may wrongly diagnose 'adrenal fatigue' or 'chronic stress' and take unnecessary actions. Home test kit quality (saliva) is not always standardized. Conclusion: daily cortisol measurements are a screening tool, not a substitute for clinical diagnosis. Persistent symptoms require medical tests (e.g., dexamethasone suppression test) and a thorough history.