Even though the efforts in research have detailed further the physiopathology and the dynamics of the frailty process an operational definition of frailty is still far from being unequivocal. Studies carried out from the SAFEs cohort study allowed a pragmatic approach in the identification of the at-risk groups for the lost of independency during the hospital stay and factors influencing their future at short-, mid- and long-term. Based upon these results, we propose to discuss the relevance of the current operational indicators of frailty in order to show that clinical markers or indicators are insufficient to differentiate the frailty process from normal ageing. Finally we give rise to the imperative necessity to detect frailty at a preclinical stage with the help of biological and more particularly inflammatory markers.