Stress occurs when there is an imbalance between a demand made on a person and the resources available to respond to the demand. The demand may be real (i.e. things outside the person's control, such as a saber-toothed tiger, or the departure time of a plane and traffic) or perceived (how the person views the situation, i.e. within or not within his/her control or sphere of influence). Similarly, the resources may be real (fact) or perceived (what you think, feel, imagine, etc).

Resources include:

• Physical ability: health, fitness and strength
• Intellectual ability: capacity for complex thinking and problem solving
• Emotional ability: accurately identifying feelings and constructively meeting needs