Abstract
This paper reports research based on interviews with 29 people with rheumatoid arthritis of at least 5 years duration. One of the topics covered was the respondents' understanding of the cause of their condition in the light of continuing medical uncertainty about aetiology. The evidence suggests that, in developing explanations, individuals will combine elements of medical knowledge with “common-sense” beliefs derived from other sources. The difference between lay and professional concepts contributes to communication problems and, in situations of chronic illness, communication may be one of the most potent components of rehabilitation. It is suggested that better appreciation of the individual's beliefs about causality could help to overcome the difficulties.