When you encounter a perceived threat, your hypothalamus, a tiny region at your brain's base, sets off an alarm system in your body. Through a combination of nerve and hormonal signals, this system prompts your adrenal glands to release a surge of hormones, including adrenaline and cortisol.

Cortisol, the primary stress hormone, communicates with the brain regions that control mood, motivation and fear. But when stressors are always present and you constantly feel under attack, that fight-or-flight reaction stays turned on.

The long-term activation of the stress-response system and the overexposure to cortisol and other stress hormones that follows can disrupt almost all your body's processes. That's why it's important to learn healthy ways to manage your stressors.