Cortisol AM(Cort AM)

Morning serum cortisol is the screening test for adrenal insufficiency. Values under 5 mcg/dL on a draw taken between 6 and 9 AM warrant a confirmatory ACTH stimulation test before diagnosis. Values above roughly 18 to 20 mcg/dL in the same window are reassuring for intact axis function in symptomatic patients. For high-performing men without primary endocrine disease, the morning cortisol is more useful as a window into chronic stress load. Persistently elevated AM cortisol associates in observational data with central adiposity, hypertension, impaired glucose tolerance, and shortened sleep duration. Persistently suppressed AM cortisol with a flat diurnal curve has been documented in overtraining syndrome, chronic underrecovery, and prolonged psychological stress, sometimes called "HPA axis flattening" or burnout physiology. The morning value alone is noisy. A single salivary or urinary cortisol curve sampled across the day (waking, 30 minutes after, noon, evening, bedtime) is far more informative than a single serum draw, and is increasingly used for stress-pattern assessment. Interventions that consistently move cortisol patterns include consistent sleep timing, reduced training load, alcohol reduction, and structured stress-reduction practices.