What is the biological importance of worrying?

Worry helps with problem-solving, and the stress reaction, also known as the fight-or-flight response, traditionally is what helped us deal with ife-threatening problems, like saber-tooth tigers. The problems with stress typically happen when we go to extremes of the anxiety scale. Some anxiety is good because it helps keep you on your toes, but too much anxiety can be destructive and no anxiety at all can mean that no decisions ever get made.