What is ‘digital health’? And what are its implications for medicine and healthcare, and for individual citizens and society? Digital health is of growing interest to policymakers, clinicians and businesses. It is underpinned by promise and optimism, with predictions that digital technologies and related innovations will soon ‘transform’ medicine and healthcare, and enable individuals to better manage their own health and risk and to receive a more ‘personalized’ treatment and care. Offering a sociological perspective, this book critically examines the dimensions and implications of digital health, a term that is often ill defined, but signifies the promise of technology to ‘empower’ individuals and improve their lives as well as generating efficiencies and wealth. The chapters explore relevant sociological concepts and theories; changing conceptions of the self, evident in citizens’ growing use of wearables, online behaviours and patient activism; changes in medical practices, especially precision (or personalized) medicine and growing reliance on big data and algorithm-driven decisions; the character of the digital healthcare economy; and the perils of digital health. It is argued that, for various reasons, including the way digital technologies are designed and operate, and the influence of big technology companies and other interests seeking to monetize citizens’ data, digital health is unlikely to deliver much of what is promised. Citizens’ use of digital technologies is likened to a Faustian bargain: citizens are likely to surrender something of far greater value (their personal data) than what they obtain from its use. However, growing data activism and calls for ‘algorithmic accountability’ highlight the potential for citizens to create alternative futures—ones oriented to fulfilling human needs rather than techno-utopian visions. This ground-breaking book will provide an invaluable resource for those seeking to understand the socio-cultural and politico-economic implications of digital health.