Most people do not share Chicken Little's fear of falling skies. Stress is, after all, largely subjective.
Additional hormones curb growth, reproduction and other nonessential activities to conserve energy.
And the brain produces more epinephrine to ready the heart and other muscles for action. In the face of danger, this short-lived reaction helps you survive. If the stress response is regularly tripped for the wrong reasons, however, it has the opposite effect. Indeed, researchers have known for some time that chronic stress often leads directly to certain illnesses, including heart disease, hypertension, depression, immune suppression and diabetes. Recently they have discovered that stress also causes developmental abnormalities, unhealthy weight gain and neurodegeneration.