What does cortisol actually do in the body?

Reviewed by Yoshinori Abe, MD

Internal Medicine

Cortisol is a steroid hormone produced by the adrenal glands that plays a key role in how the body responds to stress. It also helps regulate energy levels, blood sugar, blood pressure, metabolism, and inflammation. Because cortisol affects so many systems, both high and low levels can lead to noticeable symptoms.

If you're experiencing fatigue, unexplained weight changes, mood shifts, or other concerning signs, it's worth understanding what may be driving them. A free, instant, online symptom check can help you clarify your symptoms, identify possible causes, and guide your next steps—whether that means lifestyle changes or seeing a doctor. It takes just a few minutes and could bring you meaningful clarity today.

Reviewed for medical accuracy: 07/15/2026

Important Next Steps

Learn if low cortisol needs care Discover likely causes of cortisol symptoms Find out if cortisol is dangerous See OTC options for low cortisol Find endocrinologist for cortisol problems Understand home remedies for cortisol issues Take a cortisol symptom check now

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Explanation

Cortisol is a hormone made by the adrenal glands, which are small glands on top of your kidneys. It plays a big role in how the body deals with stress. When you feel stressed, your body makes more cortisol to help you handle it. This hormone helps by giving you more energy and keeping your blood sugar steady.

What Cortisol Does

Stress Response: Cortisol helps you react to stress by increasing energy and alertness.
Energy Balance: It helps keep your energy levels steady throughout the day.
Inflammation Control: Cortisol reduces inflammation, which is how your body fights off sickness.

Sometimes, having too much cortisol for a long time can lead to problems, like feeling tired or gaining weight. Scientists are studying how cortisol affects the brain and body, especially during long-term stress. If you're experiencing symptoms related to stress or hormonal imbalances, you can use our free AI symptom checker to better understand what might be happening with your health.

(References)

Knezevic E, Nenic K, Milanovic V, & Knezevic NN. (2023). The Role of Cortisol in Chronic Stress, Neurodegenerative .... Cells, 38067154.
Amasi-Hartoonian N, Sforzini L, Cattaneo A, & Pariante CM. (2022). Cause or consequence? Understanding the role of cortisol .... Current opinion in endocrine and metabolic research, 35634363.
Lightman SL, Birnie MT, & Conway-Campbell BL. (2020). Dynamics of ACTH and Cortisol Secretion and Implications .... Endocrine reviews, 32060528.

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