Cortisol
Cortisol is the primary glucocorticoid hormone produced by the adrenal cortex in response to ACTH from the pituitary gland. It follows a strong circadian rhythm — highest in the morning (cortisol awakening response) and lowest at midnight. Cortisol mobilizes energy, suppresses inflammation, and enables the body's stress response.
Why it matters: Chronically elevated cortisol (Cushing's syndrome) causes central obesity, muscle wasting, thin skin, osteoporosis, hypertension, and diabetes. Chronically low cortisol (Addison's disease or adrenal insufficiency) causes fatigue, weight loss, low blood pressure, and salt cravings. Both extremes are serious conditions requiring medical management.
May increase with:
May decrease with:
What is Cortisol?
Cortisol is the primary glucocorticoid hormone produced by the adrenal cortex in response to ACTH from the pituitary gland. It follows a strong circadian rhythm — highest in the morning (cortisol awakening response) and lowest at midnight. Cortisol mobilizes energy, suppresses inflammation, and enables the body's stress response.
What might a high or low Cortisol mean?
Chronically elevated cortisol (Cushing's syndrome) causes central obesity, muscle wasting, thin skin, osteoporosis, hypertension, and diabetes. Chronically low cortisol (Addison's disease or adrenal insufficiency) causes fatigue, weight loss, low blood pressure, and salt cravings. Both extremes are serious conditions requiring medical management.
What is the typical reference range for Cortisol?
The general-population reference range shown here is 171 – 536 nmol/L. Reference ranges describe the general population and are not a personal target — discuss your results with your physician.
What can affect Cortisol?
It may be higher with: Physical or psychological stress, Sleep deprivation, Cushing's syndrome (adrenal tumor, pituitary tumor, ectopic ACTH), Exogenous corticosteroid use, Obesity, Chronic pain, Excessive exercise, Depression. It may be lower with: Addison's disease (primary adrenal insufficiency), Pituitary insufficiency (secondary), Abrupt corticosteroid withdrawal, Adequate sleep and stress management, Ashwagandha (modest cortisol-lowering effect), Meditation and relaxation practices.