Back to glossary
Sleep & circadian

Cortisol awakening response

DECortisol-Aufwachreaktion

Reviewed by

The cortisol awakening response (CAR) is a sharp rise in salivary cortisol of roughly 50 percent on average (commonly reported in the range of about 38 to 75 percent) from the awakening sample to a peak about 30 to 45 minutes after waking. It reflects healthy hypothalamic-pituitary-adrenal axis activation, mobilising energy and focus for the day. A blunted or exaggerated CAR is associated with chronic stress, burnout, depression, sleep disorders, and adverse cardiometabolic outcomes, making it a useful marker in longevity and stress research.

Sources

  1. Pruessner JC, Wolf OT, Hellhammer DH et al.. (1997). Free cortisol levels after awakening: A reliable biological marker for the assessment of adrenocortical activity. *Life Sciences*doi:10.1016/S0024-3205(97)01008-4
  2. Clow A, Thorn L, Evans P, Hucklebridge F. (2004). The awakening cortisol response: methodological issues and significance. *Stress*doi:10.1080/10253890410001667205