Cortisol
The primary stress hormone, measured in the morning when it peaks.
What is it
Cortisol is produced by the adrenal glands following a circadian rhythm. Morning measurement captures the daily peak and is used to evaluate adrenal function.
Why it's measured
Cortisol has been studied in research on stress, sleep, metabolism, and adrenal function. Both elevations and deficiencies have clinical significance.
Reference range
Standard laboratory reference
6 – 18 (morning) μg/dL
Reference ranges vary by laboratory. Your individual reference range will appear on your test report and should be interpreted by your physician in the context of your overall health profile.
What results may indicate
Elevated
Has been associated with chronic stress, Cushing's syndrome, and certain medications in research literature.
Lower
Has been associated with adrenal insufficiency and warrants clinical evaluation.
These associations are general. They are not a personal diagnosis or prediction. Discuss your individual results with your physician in the context of your full health profile.
When it's measured
Typically measured between 6–9 AM when levels naturally peak.
Related markers
Measured in
A complete look at your heart, hormones, metabolism, inflammation, and longevity systems — drawn at Quest or LabCorp, reviewed by a U.S.-licensed physician.
Explore the Apex Panel →This information is for general educational purposes only and is not medical advice. Lab results alone are not intended to diagnose, treat, or cure any condition and do not replace the advice of a healthcare provider. OPTML does not offer medical advice, a diagnosis, medical treatment, or any form of medical opinion.