We live in the digital age. Digital technology is changing all aspects of our lives, including how we work and spend our leisure time, how we relate to others, and even how we think. Although late compared with other industries, digital technologies are now deeply penetrating health care. In this commentary, I survey and appraise “digital health,” which “harnesses the transformational power of modern information and communication technologies for improving health and healthcare.”1 I first briefly consider how massive amounts of data are being collected, analyzed, and applied to health and health care.