Myths vs facts: Cortisol and Schlaf

Cortisol and sleep are closely linked, but myths abound. Fact: Cortisol follows a circadian rhythm – high in the morning, low at night. Disruptions (chronic stress, shift work, sleep deprivation) can elevate evening cortisol, impairing sleep onset and quality. Myth: Cortisol is always harmful. In reality, it is essential for energy regulation and immune function. Another myth: One good night of sleep immediately normalizes cortisol. Evidence shows it takes several days of consistent sleep to restore the rhythm. Also, the idea that only major stress affects cortisol is false – daily hassles matter too. The evidence is strong (human studies), but no specific sources were provided in the context. Practical takeaways: Prioritize sleep hygiene, stress reduction, and regular exercise. Single cortisol measurements (e.g., saliva) are snapshots, not diagnostic for chronic conditions. Avoid overinterpreting consumer tests that claim to 'optimize' cortisol without clinical context.