The primary stress hormone that regulates metabolism, immune response, and the body's fight-or-flight response.
FULL EXPLANATION
Cortisol is a glucocorticoid hormone produced by the adrenal glands in response to stress and low blood glucose. It follows a diurnal pattern, naturally peaking in the morning to help you wake up and declining throughout the day.
While cortisol is essential for survival and normal function, chronically elevated cortisol from ongoing stress can lead to weight gain (especially abdominal), muscle loss, impaired immunity, sleep problems, and mood disorders.
WHY IT MATTERS
Proper cortisol regulation is essential for energy, metabolism, immune function, and recovery. Chronic elevation accelerates aging and increases disease risk.
HOW TO IMPROVE
Manage cortisol through stress reduction techniques, regular exercise (but not overtraining), adequate sleep, social connection, and adaptogenic herbs if appropriate.
NORMAL RANGES
Morning cortisol: 10-20 mcg/dL. Evening: 3-10 mcg/dL. Should show significant diurnal variation. Salivary cortisol testing is often more practical.
RELATED TERMS
Circadian Rhythm
The roughly 24-hour internal biological clock that regulates sleep-wake cycles, hormone release, and other physiological processes.
Testosterone
The primary male sex hormone responsible for muscle mass, bone density, libido, and overall vitality in both sexes.
Heart Rate Variability
The variation in time between consecutive heartbeats, a key indicator of autonomic nervous system function and overall health.
Overtraining Syndrome
A condition of decreased performance and fatigue that occurs when training exceeds recovery capacity for an extended period.
More in Hormones & Endocrine
View all →Insulin
Well-EstablishedA hormone produced by the pancreas that regulates blood sugar by promoting glucose uptake into cells.
Testosterone
Well-EstablishedThe primary male sex hormone responsible for muscle mass, bone density, libido, and overall vitality in both sexes.
Thyroid Hormones
Well-EstablishedHormones produced by the thyroid gland that regulate metabolism, energy, body temperature, and growth.