公共卫生是预防疾病的科学和艺术，其目的是提高生活质量，以循证医学为基础。它基于人口健康分析关注对健康的威胁。所涉及的人口可能只有少数几个，也可能与几个大洲的所有居民一样大。根据联合国世界卫生组织（WHO）的定义，健康的各个方面可以涵盖一个完整的身体，心理和社会健康状况，而不仅仅是疾病或虚弱。公共卫生结合了流行病学，生物统计学和多种卫生服务的跨学科方法。包括教育工作者，新闻工作者，研究人员，管理人员，环境科学家，人口统计学家，社会工作者，实验室科学家等在内的许多专家致力于保护公众健康。公共卫生专业人员在环境
Public health is the science and art of preventing illness and disease and promoting evidence-based health practices with the goal of improving the quality of life. It is concerned with threats to health based on population health analysis. The population in question can be as small as a handful of people, or as large as all the inhabitants of several continents. The dimensions of health can encompass a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity, as defined by the United Nations World Health Organization (WHO). Public health incorporates the interdisciplinary approaches of epidemiology, biostatistics and a vast array of health services. A host of specialists including educators, journalists, researchers, administrators, environmental scientists, demographers, social workers, laboratory scientists and more, work to protect the health of the public. Public health professionals serve local, national and international communities in settings such as environmental health, occupational health, community health, behavioral health, health economics, public policy and insurance. Public health is a very rewarding field offering great personal fulfillment in serving others.