ELI5: What is cortisol?

Cortisol is like your body's built-in alarm system, helping you deal with stress.

Imagine you're a little kid playing in the park, and suddenly a big dog starts barking at you. Your body needs to get ready to run away or deal with the scary dog! That's when cortisol comes to the rescue.

• It's a special chemical, a hormone, made in a part of your body called the adrenal glands.
• When you feel stressed (like seeing that dog), your brain tells the adrenal glands to release cortisol.

• Gives you energy: It helps release sugar into your blood, so your muscles have fuel to run or fight. Think of it as pouring extra gasoline into your car's tank.
• Focuses your attention: It makes you more alert and aware of what's happening around you, so you can react quickly. It helps you see the dog clearly and think about what to do.
• Slows down other things: While you're dealing with the stress, cortisol tells your body to put other jobs, like digestion or growing, on hold. This saves energy for the important task of dealing with the stressor.

• Feel tired and cranky.
• Have trouble sleeping.
• Get sick more easily.