Lay opinion vs evidence: Cortisol Test

Cortisol tests (saliva, blood, urine) are clinically validated for diagnosing Cushing's syndrome, adrenal insufficiency, and other endocrine disorders. Lay opinion often overestimates their utility for measuring daily stress or burnout risk. The evidence is mixed: strong for clinical endocrinology (human-moderate), but weak for wellness stress assessment. Single cortisol measurements are highly variable due to circadian rhythm, acute stress responses, and methodological issues. Consumer test kits (e.g., saliva) often lack standardization and cannot reliably indicate chronic stress. Psychological factors like perceived stress also influence results. Conclusion: Cortisol tests are medically useful when endocrine disease is suspected, but not as a biomarker for everyday stress. Lay opinion significantly overstates their value.