Unfortunately, when we speak about modern day stress, we are usually referring to the bad kind of stress that makes the quality of our lives worse.
The underlying biological mechanism of stress is intended to provide a benefit for a short amount of time. If we try to abuse this mechanism, it causes damage instead.
Why does bad stress happen? If we lose sight of our priorities in life, if we neglect our physical bodies, if we recklessly push beyond our limitations, if we close our hearts and minds in fear, if we are greedy or inconsiderate, if we are conflicted within - these things lead to bad stress.
You can't be high-strung all the time without paying the price. Most of bad stress can be avoided by asking yourself a simple question: "Is this really worth getting stressed over?"
Value your time, value your life! Don't sweat the small stuff.