Biomarker Reference · C0
Awakening Cortisol (C0) is a clinical biomarker used in adrenal-stress assessment. Cortisol secretion follows a circadian rhythm driven by the suprachiasmatic nucleus and the hypothalamic-pituitary-adrenal axis. It is measured in 2 laboratory tests on BiomarkersLabs.com.
Cortisol secretion follows a circadian rhythm driven by the suprachiasmatic nucleus and the hypothalamic-pituitary-adrenal axis. Upon waking, cortisol concentration rises sharply — a phenomenon termed the cortisol awakening response (CAR) — reaching a peak 30–45 minutes after waking. The awakening sample captures the nadir before this surge begins and anchors interpretation of the subsequent rise.
The baseline awakening cortisol level provides context for the magnitude of the cortisol awakening response. A blunted or absent CAR, where the 30- or 45-minute post-waking value fails to rise meaningfully above the awakening baseline, has been associated with chronic stress, burnout, and certain psychiatric and inflammatory conditions, though the clinical utility of the CAR remains an area of active research.
Reference ranges vary by laboratory and assay platform. Interpret in context of the issuing laboratory's stated range.
2 tests on BiomarkersLabs.com include this biomarker.
Awakening Cortisol reference range in this test: Laboratory-specific; typically 10–40 nmol/L in saliva at awakening.
Awakening Cortisol reference range in this test: Laboratory- and collection-time specific; typically 10–40 nmol/L at waking.
Available exclusively to verified licensed healthcare practitioners. CLIA-certified laboratory results delivered to your secure portal.
Create Free Account