An official website of the United States government
Here’s how you know
Official websites use .gov A
.gov website belongs to an official government
organization in the United States.
Secure .gov websites use HTTPS A
lock (
) or https:// means you’ve safely connected to
the .gov website. Share sensitive information only on official,
secure websites.
Imagine you're getting ready to race. The stress you feel makes your brain signal the adrenal glands to produce epinephrine or "adrenaline". Adrenaline increases your heart rate. As a result, more oxygen gets to your muscles. That makes your body ready to react. In a longer-term response to stress, the glands secrete cortisol. Cortisol promotes the release of energy, making you ready to race.
Review Date 4/18/2024
Updated by: Linda J. Vorvick, MD, Clinical Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.