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# Cortisol

cor·ti·sol - KOR-tih-sol

## Definition

Cortisol is a steroid [hormone](/glossary/hormone) produced by the adrenal glands (small glands sitting atop each kidney) that plays a central role in the body's stress response and dozens of essential daily functions. Often called the "stress hormone," cortisol is released in higher amounts when the brain perceives a threat or stressful situation, mobilizing the body's resources for a [fight-or-flight response](/glossary/stress-response).

But cortisol's role extends far beyond stress. It helps regulate blood sugar levels by stimulating glucose production in the liver, influences how the body metabolizes fats and proteins, helps control [blood pressure](/glossary/blood-pressure), reduces inflammation, assists with memory formation, and regulates the [sleep-wake cycle](/glossary/circadian-rhythm). Cortisol levels naturally follow a circadian pattern - they're highest in the early morning (helping you wake up and feel alert) and lowest at night (allowing you to sleep).

Problems arise when cortisol levels are chronically elevated or abnormally low. Chronic stress keeps cortisol elevated, which over time can lead to weight gain (especially around the abdomen), impaired immune function, disrupted sleep, anxiety and depression, elevated blood sugar, [high blood pressure](/glossary/hypertension), and cognitive impairment. Conversely, abnormally low cortisol (as in Addison's disease) causes fatigue, weight loss, low blood pressure, and potentially life-threatening adrenal crises.

## Also Known As

Stress hormone Hydrocortisone (synthetic form) 

## Key Facts

-   • Cortisol levels are typically highest between 6-8 AM and lowest around midnight. 
-   • Chronic stress can keep cortisol elevated for prolonged periods, contributing to numerous health problems. 
-   • Cortisol suppresses the immune system - which is why corticosteroid medications are used to treat autoimmune and inflammatory conditions. 
-   • The cortisol awakening response (CAR) - a spike in cortisol within 30 minutes of waking - is a normal part of the body's daily rhythm. 
-   • Exercise temporarily raises cortisol but regular physical activity helps normalize the overall cortisol response to stress. 
-   • Mindfulness meditation has been shown in multiple studies to reduce cortisol levels and improve stress resilience. 

## How It Relates To Your Health

Understanding cortisol helps explain why chronic stress affects so many aspects of health. If you're experiencing persistent fatigue, difficulty sleeping, weight gain around the midsection, frequent illnesses, anxiety, or [brain fog](/glossary/brain-fog), chronically elevated cortisol may be a contributing factor. While cortisol testing is available, single measurements can be misleading because levels fluctuate significantly throughout the day.

Managing cortisol naturally involves addressing the root causes of chronic stress through regular exercise, adequate sleep, mindfulness practices, social connection, and setting appropriate boundaries. These lifestyle strategies don't just make you feel better - they produce measurable reductions in cortisol levels and improvements in the biological systems cortisol influences.

## Related Terms

[Dopamine](/glossary/dopamine)[Serotonin](/glossary/serotonin)[Metabolic Syndrome](/glossary/metabolic-syndrome)[Insulin Resistance](/glossary/insulin-resistance)

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## Sources

1.  [Cortisol](https://my.clevelandclinic.org/health/articles/22187-cortisol) - Cleveland Clinic
2.  [Physiology, Cortisol](https://www.ncbi.nlm.nih.gov/books/NBK538239/) - StatPearls / PubMed
3.  [Chronic stress puts your health at risk](https://www.mayoclinic.org/healthy-lifestyle/stress-management/in-depth/stress/art-20046037) - Mayo Clinic

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