Fatigue: a summary of the definitions, dimensions, and indicators.

Fatigue is a universal complaint that may or may not be related to medical diagnoses or therapeutic treatment. Fatigue is a complex, multicausal, multidimensional, nonspecific, and subjective phenomenon for which no one definition is widely accepted. The absence of theories concerning the nursing diagnosis of fatigue limits insight into the phenomenon and hinders the development of valid and reliable instruments for the measurement of fatigue. Therefores, the authors have undertaken a concept of analysis of fatigue, to a) document how it is defined in the literature; b) which dimensions of the concept of fatigue are distinguished; and c) which indicators of both the content and forms of fatigue represent the concept in practice. This concept analysis has resulted in a theoretical frame of reference that can indicate directions not only for further research into the nursing diagnosis of fatigue, but also for the development of measuring instruments.