Health and illness are universal human experiences, yet how they are understood, perceived, and lived varies widely across individuals and populations. These differences are shaped by the social, cultural, and environmental contexts in which people live, as well as by the choices they make throughout the life course. Health behaviors—whether protective or harmful—play a pivotal role in shaping health outcomes. Behaviors such as dietary practices, alcohol use, smoking, physical activity, sexual health behaviors, medication adherence, preventive screening, and vaccination can either reduce vulnerability to disease or heighten health risks. Understanding these behaviors across both healthy and at‑risk populations remains a central priority in public health and is essential to improving population health worldwide.Equally important, individual behavior does not occur in isolation. As emphasized by the World Health Organization, health is profoundly shaped by the conditions in which people are born, grow, live, work, and age. Social, economic, political, cultural, and environmental factors systematically influence health opportunities and outcomes, contributing to persistent health inequities. These broader determinants of health—and their intersections with individual behavior—form a central focus of this handbook and the wider series.This volume is the inaugural title in a handbook series on health behavior and illness prevention, commissioned by Springer in Singapore. It brings together authoritative, interdisciplinary perspectives on core health concepts, health behavior, environmental health, health promotion, health literacy, intervention design, and research methods. Structured across three books and multiple thematic parts, the series provides a comprehensive framework for understanding and addressing health behavior and illness prevention at individual, community, and societal levels.The present handbook addresses foundational concepts of health, the nature and determinants of health behavior, and the environmental conditions that shape both. It integrates theory with practice and adopts a critical, equity‑focused perspective. Rather than privileging deficit‑based or individual‑blame models, the volume situates health‑compromising behaviors within broader structural and systemic contexts. For example, limited health literacy may reflect unequal access to education, which itself is often rooted in marginalization, poverty, and power imbalances. By unpacking these deeper drivers, the handbook advances a more just and nuanced understanding of health behavior.Contributors include leading researchers, educators, and practitioners specializing in health, health behavior, and environmental health. Their collective expertise enriches current understanding of health and illness prevention and offers evidence‑informed insights to support policy, practice, and research. This handbook will be an essential resource for students, scholars, and professionals across the health sciences who seek to advance health equity and improve population well‑being globally.
