Healthcare and well-being have captured the attention of established software companies, start-ups, and investors. Software is starting to play a central role for addressing the problems of the aging society and the escalating cost of healthcare services. Enablers of such digital health are a growing number of sensors for sensing the human body and communication infrastructure for remote meetings, data sharing, and messaging. The challenge that lies in front of us is how to effectively make use of these capabilities, for example to empower patients and to free the scarce resources of medical personnel. Requirements engineering is the process by which the capabilities of a software product are aligned with stakeholder needs and a shared understanding between the stakeholders and development team established. This book provides guide for what to look for and do when inquiring and specifying software that targets healthcare and well-being, helping readers avoid the pitfalls of the highly regulated and sensible healthcare domain are and how they can be overcome. This book brings together the knowledge of 22 researchers, engineers, lawyers, and CEOs that have experience in the development of digital health solutions. It represents a unique line-up of best practices and recommendations of how to engineer requirements for digital health. In particular the book presents: The area of digital health, e-health, and m-health Best practice for requirements engineering based on evidence from a large number of projects Practical step-by-step guidelines, examples, and lessons-learned for working with laws, regulations, ethical issues, interoperability, user experience, security, and privacy How to put these many concerns together for engineering the requirements of a digital health solution and for scaling a digital health product For anybody who intends to develop software for digital health, this book is an introduction and reference with a wealth of actionable insights. For students interested in understanding how to apply software to healthcare, the text introduces key topics and guides further studies with references to important literature.