Chronic illness lasts. A chronic illness has a lengthy duration, uncertain outcome, and unpredictable episodes, often with intrusive symptoms and intermittent or progressive disability. Having a chronic illness poses life problems such as following a medical regimen, managing ordinary responsibilities, and experiencing stigma and discrimination. A disease, in contrast, may remain silent for years without eliciting a diagnosis or causing noticeable symptoms and life disruptions. Experiencing chronic illness makes disease real. Sociological definitions of chronic illness start with the experience of disruption and impairment. In contrast, early disability theorists defined disability as starting from the lack of societal accommodation to individuals’ needs, thereby resulting in disadvantage and discrimination. This definition of disability presupposed that people had static, visible physical conditions with predictable and sustained needs, such as those with certain neuromusculoskeletal conditions. Many researchers have long viewed disability as fluid, often invisible, and leading to unanticipated changing needs. Hence they also study people with a wide range of conditions such as mental illnesses, autism, developmental disabilities, learning disabilities, and multiple chemical sensitivities. In the past decade, the sociological definition of disability has become an increasingly contested area. Disability theorist Tom Shakespeare (2014) has rejected the social definition of disability and acknowledges the significance of impairment, as medical sociologists have demonstrated for decades (Bury, 1982; Charmaz, 1995; Simon, 1999; Strauss et al., 1984). Chronic illness and disability first emerged as fields of sociological inquiry in early ethnographic studies such as Roth 1963, Goffman 1963, and Davis 1963. These sociologists’ depiction of patients’ actions and interactions with professionals contrasted with Talcott Parsons's (1953) theoretical concept of the sick role which assumed recovery from illness, successful medical intervention, and passive patients. Parsons's concept of the sick role fit neither the treatment goals for chronic illness and disability nor their corresponding treatment roles. Illness continues, disability persists. Hence, physicians treat symptoms rather than causes, attempt to minimize complications, and rely on patients and their caregivers for information, but monitoring and managing occur at home.