According to a high school psychology textbook, stress is "a particular pattern of disturbing psychological and physiological reactions that occur when an environment event threatens important motives and taxes one's ability to cope."
In plain English, stress is the "wear and tear" our bodies experience as we adjust to our continually changing environment.
But not all stress is bad -- some stress is good. In fact, everyone needs stress in their lives; without it, life would be dull and unexciting. Stress adds flavor, challenge and opportunity to life. Stress can pump you up, give you energy, supply that zest for living.
Stress is an unavoidable part of life. The challenges caused by stress help to develop new skills and behavior patterns. The problems occur, however, when stress becomes excessive. It can become destructive and can turn into distress. Too much stress on your mind and body can make you feel miserable, worried, sad and ill.
Contrary to popular belief, stress is not the pressure from the outside--the divorce, the death, the burned supper, the vacation, the isolation. Those are stressors. Your response to those situations constitutes stress.