Disability is often described in a way that suggests that it is a permanent and relatively stable state. Even when it is described as being socially constructed, the implication is that impairment leads to a permanent status of being 'disabled'. This volume argues that the relationship between impairment (physical state) and disability is neither fixed nor permanent but is fluid and not easily predicted. Furthermore, if this is true, we need to rethink how we are measuring disability. This volume attempts to reconceptualize disability not as static but a dynamic phenomenon which is related to social, cultural and historical contexts. It is part of the new social science emphasis on fluidity rather than stasis. The papers in the volume examine disability at all levels. Several look at micro-level interactional processes which shape physical conditions into disabilities or impairments into normality, some look at cultural differences over time in what constitutes disability and some look at how social processes and institutions create or deny the status of disability. The papers support the conceptualization of the fluidity of disability and have implications for its measurement.