Ill-health changes the anatomy and physiology of affected organs, some of which can be observed visually, elicited through physical examination or confirmed through biomedical analysis. Understanding how anatomical changes contribute to physiological signs and symptoms will help practitioners identify the pathology, appreciate its origin and development and justify prescribed interventions in a way which can be upheld by critical external scrutiny. Reflexology contributes to an holistic approach to care and has recently improved its credibility as a discipline which supports orthodox care. Several research publications have identified possible theories and principles for the mechanism of action of reflexology, but more research to explain its contribution in identifying ill-health and diseases, as well as appropriate treatment modalities, is needed. This paper explores the physiological basis of reflexology, some of the theories for the mechanism of action and its potential as a diagnostic tool.