The stress is defined as a self perceived negative or unpleasant impact. Distress is reserved for the experience of specific symptoms such as anxiety or depression. The term stressor covers some environmental circumstances directly or indirectly affecting the individual. As Selye has suggested, we must remember that stress is the great equalizer of biological activities. If we use the same parts of our bodies or minds over and over again, nature has only stress with which to face us out of the routine. As a consequence, unhealthy levels of stress lead to a variety of disorders and illness.