Using autoimmune strategically: Diagnostic lumping, splitting, and the experience of illness.

Experience of illness and sociology of diagnosis literatures offer valuable insights into how people live with chronic illness. In this article, we argue that investigating autoimmune illnesses contributes to the sociological understanding of illness experiences and diagnosis practices. Autoimmune is a broad category of illnesses in which a person's immune system identifies healthy cells as pathological. Drawing on 45 in-depth interviews with people who live with autoimmune illnesses, this article shows how both broad diagnostic classifications (lumping) and narrow diagnostic classifications (splitting) are integral to diagnostic work and illness experiences. Combining the illness experience and sociology of diagnosis literatures, we theorize diagnosis as an iterative process in which people strategically use broad illness categories such as autoimmune in combination with specific illness categories such as multiple sclerosis a way to negotiate heterogeneity and uncertainty and to make sense of what is happening in their bodies. In this article, we argue that in an era of specialization, broad diagnostic categories can help both patients and clinicians navigate the experience of illness.