Occupational engagement is a pre-requisite for continuous income opportunities. Among the changing social circumstances work-related conditions play an increasingly eminent role in psychological and mental well-being. The public discusses the question of a possible association between the demands of modern work life and the increases of psychological, psychosomatic and cardiovascular disorders. Given the socioeconomic implications of psychiatric and psychosomatic suffering in the general population, there is a need to further elucidate the causes of their increasing incidence. From a medical point of view, any organization of work disrupting the phased circadian rhythms for bio-psycho-social processes and functioning of the individual are interesting against the background of clock genes and certain biological functions that are organized in a circadian fashion. The authors review the influence of shift work as a form of systematic desynchronization of inner clock systems on the endocrine, the physical, and the mental level. The significance of the findings in the field is discussed along with future directions of conclusive research.