Does cortisol affect glucose?
Yes. Cortisol raises hepatic glucose output and antagonizes insulin. Chronic stress and sleep loss raise cortisol, which raises fasting glucose and contributes to insulin resistance.
Full answer
Cortisol is the body's primary glucocorticoid and raises blood glucose through hepatic gluconeogenesis and insulin antagonism. Acute stress, chronic stress, and sleep loss elevate cortisol and contribute to fasting hyperglycemia and insulin resistance over time. Exogenous corticosteroids do the same. Cushing's syndrome causes overt hyperglycemia. Within the assessment, persistent fasting hyperglycemia despite reasonable lifestyle prompts review of sleep, stress, alcohol, and (rarely) a cortisol workup. Sleep and stress optimization are first-line.
Educational. Not a substitute for individualized provider review.
- Methodology — Primary source · oMeds
- Reviewed by Dr. Laura Purdy, MD, MBA · Clinical Director, oMeds · Last reviewed 2026-06-03