Skip to ContentGo to accessibility pageKeyboard shortcuts menu
OpenStax Logo

2.1 Defining Public Health

Health should be attainable for all people. Public health facilitates health for all through organized efforts to prevent disease, reduce risk and disparities, and promote health. Educational programs, policies, health services, research, and direct care are all part of public health. While public health addresses the upstream and downstream factors of health conditions, its focus is upstream factors. Public health differs from population health in the focus and scope of work. Population health focuses on actions and initiatives of the health system to improve health outcomes. Public health involves collective action, public policy, governance, and health services to promote and protect the health of the population. Both specialty arms aim to achieve favorable health conditions for all.

2.2 Historical Perspectives on Public/Community Health

Historical events have shaped public health as a field and group of services. For example, the Industrial Revolution inspired changes to public health policies surrounding sanitation, workplace safety, and the existence of public health departments. Changes such as reforms in worker safety, sanitation, and establishing public health departments were driven by collective action and societal pressure. Concerns regarding environmental health threats and worker health remain, highlighting the need for ongoing public health efforts and a strong public health workforce. The work of public health in supporting health for all continues today. Public health activities, guidelines, policies, and regulations are essential in promoting health, reducing risk, preventing disease, and advocating for the health of all.

2.3 The Importance of Public/Community Health

Collaboration is needed to improve the nation’s health. Different entities share data, resources, expertise, and programming to comprehensively improve public health. Collaborations may involve coordinating care services, applying the population perspective to clinical practice, identifying and addressing public health problems, and strengthening health promotion and risk reduction to provide a holistic approach to addressing complex health issues. Healthy People 2030 identifies priority actions and tactics for improving public health that are reviewed and used to shape local policies and programming. Public health plays a critical role in supporting population health. The strategies and policies that public health systems develop, promote, or enforce all reduce the burden of disease and risk to improve the general population’s health.

2.4 The Core Functions and Essential Services of Public Health

The CDC identified 10 Essential Public Health Services that can be used to guide health promotion and protection activities. Essential services include assessing population health, investigating and addressing health problems, effective communication, community mobilization, policy development, legal actions, equitable access to care, building a skilled workforce, evaluation and research, and supporting organization infrastructure. The essential services align, and work in concert, with the three core functions of public health: assessment, policy development, and assurance. Assessment involves collecting and evaluating health data, policy development involves creating regulations supportive of health, and assurance supports access to services for everyone.

2.5 Levels of Prevention

The five levels of prevention in public health are primordial, primary, secondary, tertiary, and quaternary. Primordial prevention focuses on reducing risk factors for the public through social change and large-scale policy. Primary prevention aims to prevent adverse health outcomes, especially in high-risk populations or individuals. Tertiary prevention involves treatment to minimize the negative impact of a health condition and prevent complications. When professionals work to protect individuals from unnecessary interventions, they are engaging in quaternary prevention. Initiatives at each level contribute to promoting health and reducing the burden of disease.


This book may not be used in the training of large language models or otherwise be ingested into large language models or generative AI offerings without OpenStax's permission.

Want to cite, share, or modify this book? This book uses the Creative Commons Attribution License and you must attribute OpenStax.

Attribution information
  • If you are redistributing all or part of this book in a print format, then you must include on every physical page the following attribution:
    Access for free at
  • If you are redistributing all or part of this book in a digital format, then you must include on every digital page view the following attribution:
    Access for free at
Citation information

© Apr 26, 2024 OpenStax. Textbook content produced by OpenStax is licensed under a Creative Commons Attribution License . The OpenStax name, OpenStax logo, OpenStax book covers, OpenStax CNX name, and OpenStax CNX logo are not subject to the Creative Commons license and may not be reproduced without the prior and express written consent of Rice University.