Healthcalendar_todayLast updated: Apr 2026
What is Cortisol?
/ˈkɔːtɪzɒl/
Cortisol is the body's primary stress hormone, released by the adrenal glands in response to stress and low blood sugar. It triggers the "fight or flight" response and plays a key role in metabolism.
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Everyday Example
When your alarm goes off for a big presentation, your heart races and your mind sharpens — cortisol flooding your bloodstream is responsible for that response.
publicReal-World Application
“Chronic high cortisol — from sustained work stress, poor sleep, or anxiety — is linked to weight gain around the abdomen, impaired memory, weakened immunity, and higher cardiovascular risk.”
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Did you know?
Cortisol was first isolated and identified in the 1930s by chemist Edward Kendall, who later won the Nobel Prize for synthesising cortisone to treat rheumatoid arthritis.
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Key Insight
Cortisol is essential for survival in short bursts but damaging when chronically elevated. Modern chronic stress keeps cortisol high in contexts where it was designed for brief physical emergencies.
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