Fibromyalgia is a disorder in which patients experience chronic pain and other symptoms, and annual medical expenditures are comparable to rheumatoid arthritis. Because fibromyalgia symptoms are “invisible,” patients also suffer from a lack of understanding and recognition. They face a difficult, long-term information seeking and sense-making task as they endeavor to manage their condition. This study explored the illness journeys of fibromyalgia patients, including how patients’ views of illness and of health evolve over time, what role information plays, and how their participation in online communities, Facebook, Twitter, and other social media changes. Participants shared their “illness journeys” through a timeline construction activity, and we explored participants' participation histories using an interface developed for this study, the Online Scrapbook. The data were analyzed through a qualitative approach drawn from Grounded Theory and Interpretative Phenomenological Analysis. This study has contributed to our knowledge of information behaviors in relation to fibromyalgia and other chronic illnesses in various ways. The study provided rich detail concerning the illness journey, and illustrated how different phases of the journey were associated with particular types of information behaviors. With regard to information behavior, the dissertation elaborates on the lessons that patients learned, information sources used, patients’ information interactions with others, and online participation. The study findings have implications for clinical care, information and interface design, and theoretical aspects of the study of information behavior. In terms of clinical care, there is a need to prepare physicians to work with fibromyalgia patients and to promote alternative medicine and lifestyle changes earlier in their illness journeys. In terms of design, there are implications for improving health discussion forums, facilitating analysis of complex clinical histories, and making information accessible and understandable. This study also has theoretical implications. There is a lack of a framework that describes the interrelatedness of the physical, emotional and cognitive elements of life, with information. A new Evolving Information Ecology model is proposed that conceptualizes the illness journey as a process in which these elements are interwoven. In addition, a taxonomy for conceptualizing long-term information exchanges is proposed.