International Journal of Clinical & Medical Images

In 1946 World Health Organization (WHO) defined health as “a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity.” [4,5]. The definition reflected the Bio-psychosocial (BPS) model of health. Moreover, in 1977, American Psychiatrist George L. Engel introduced a general theory of illness and healing [2,3] in the health sector, the Bio-psychosocial (BPS) model (Figure 1). In fact within the BPS model, three basic criteria of unhealthy [1] are included: 1. ‘Disease’ conceptualized as a pathological term (Biological) 2. ‘Illness’ is thought as an internal, individual experience (Psychological). 3. ‘Sickness’ is considered as an external, public mode involving interaction between the person, other people and environment (Sociological). The BPS model interconnected biological, psychological, and sociological factors as a system of the body and health which showed a dramatic shift in focus from disease to health.