Medicine & Health
What is Cortisol?
Cortisol is a hormone released by the adrenal glands that helps your body respond to stress and regulate energy, blood sugar, and inflammation. Known as the 'stress hormone', it follows a daily rhythm — high in the morning to wake you, lower at night.
See it, don’t just read it.
Watch a 2-minute lesson with voice + animation that explains cortisol.
Key things to understand
- 1It is produced by the adrenal glands, which sit on top of the kidneys, under the brain's control.
- 2It rises during stress, raising blood sugar and alertness for 'fight or flight'.
- 3It follows a daily curve: highest soon after waking, lowest around midnight.
- 4It also helps regulate metabolism, blood pressure, and the immune response.
- 5Chronically high cortisol from long-term stress can harm sleep, mood, and health.
Frequently asked questions
- Is cortisol bad for you?
- No — it is essential for waking up, handling stress, and regulating metabolism. The problem is chronically high levels from constant stress, not cortisol itself.
- How can I lower high cortisol?
- Regular sleep, exercise, and stress management — and treating any underlying medical cause — help bring chronically elevated cortisol back toward a healthy rhythm.
- Why is cortisol highest in the morning?
- A morning surge helps wake you and mobilize energy for the day, then it tapers off so levels are lowest at night for sleep.