Article / Updated 03-26-2016
One way of defining stress is the body's response to a change or challenge. The change or challenge that causes the stress is called a stressor, which could be anything from the freezing temperature outside, to a new medicine you're taking, to an attack dog that's charging after you!
Acute versus chronic stress
During the stress response, energy is diverted from your immune, digestive, and reproductive systems and focused on giving you a supreme burst of energy.