This book serves as a roadmap for the development and application of patient-reported outcome (PRO) measures, supporting beginners through to experts, as a practical guide. To elucidate on key concepts in the book, examples from clinical research in hyperhidrosis and health-related quality of life and medicines clinical development context, are used. Health-related quality of life represents one of the most commonly measured PROs in both routine clinical practice and research. The book demonstrates the importance of PROs to patients with chronic disease and how such outcomes can assist clinicians in managing patients and monitoring their response to treatment in terms of both symptoms and impacts. This book will benefit readers as a single-source practical guide on the development of modern PRO measures and may also serve as a blueprint for the conceptualization and planning of evidence generation related to PROs in various settings.  Ideas and suggestions on how to navigate recent developments shaping the field of PRO measurement are also offered.