Biologic stress is not the same as nervous tension. Selye described an environmental view of stress in terms of change and adaptation dictated by life events. Over time, persistent stress may cause the body to adapt—to permanently change, possibly in unhealthy ways. Quality of adaptation to psychological, physical, social, and economic stressors determines quality of life. Failure to adapt leads to what Selye called diseases of adaptation.
According to neuroscientist Robert Sapolsky, human beings and related primates suffer stress-related diseases more than any other animals. Man is a smart, organized, social creature with too much spare time and uses that time to stress each other out. According to Sapolsky, “we’ve evolved to be smart enough to make ourselves sick.”