Pain: towards a comprehensive understanding and a definition

Pain is the most prominent - though not the commonest - symptom from which patients suffer, yet no one has been able to define it. It is proposed that pain is a signal of the involuntary monitoring system of the body manifesting itself as a conscious sensation. The construction of a monitor is discussed and examined as a model for understanding pain. The relationship between fatigue and pain is stressed. The understanding of fatigue is seen as an essential prerequisite for the definition or conceptualisation of pain. The question is raised as to whether pain is a measureable entity.