Cortisol Awakening Response

The DUTCH CAR (Cortisol Awakening Response) is an excellent snapshot of HPA axis function and can be used as a ‘mini stress test.’ Thirty minutes after waking cortisol levels will increase by an average of 50%. By 60 minutes they will have peaked and started to decline. The rise and fall of the CAR can be measured using salivary swabs upon waking and at 30 and 60 minutes after waking. A low CAR can be a result of an underactive HPA axis, psychological burnout, seasonal affective disorder (SAD), sleep issues, PTSD, chronic fatigue, chronic pain, hypertension, gastrointestinal issues, post-natal depression and autoimmune disease. An elevated CAR can be the result of an overactive HPA axis, anticipatory stress, glycaemic dysregulation, pain and depression.