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Definitions: what is public health?

In this article learn about the different ways 'public health' was defined throughout the last 70 years of British history.
A bike displaying the slogan 'this is public health'.
© London School of Hygiene & Tropical Medicine
Here we show how the idea of public health and its definition have either evolved or remained the same in Britain since World War II.
What is ‘public health’? Is it about the well-being of the population? Is it about the provision of certain health services? Is it about clean water and air, or encouraging people to give up smoking and fast food? This seemingly simple question defies a simple answer!
Throughout the course we will suggest that public health is all of these things and more. Indeed, when we think about how public health has changed over time, the picture becomes even more complex. In the nineteenth century, for instance, the primary public health concern was combating infectious disease; today we are more focused on chronic conditions like diabetes and obesity. To tackle the question of ‘what is public health’, we will look at the changing meaning of public health in three dimensions: public health as a way of thinking; as a set of structures and services; and as a collection of challenges and solutions. In this step, we will focus on public health as a way of thinking.

What is ‘health’?

Let’s begin by considering what is meant by ‘health’. In 1948, the World Health Organization defined health as: “a state of complete physical, mental and social wellbeing and not merely the absence of disease or infirmity.” 1 This is a very broad definition of health, but it is one that has had a significant impact, and despite being over 70 years old, you will often see it repeated.

What is the ‘public’?

What about the meaning of the ‘public’? We can break this down into two aspects. Firstly, ‘public’ implies a group of people rather than just one, whether that be a specific community or the whole population. Secondly, ‘public’ refers to collective rather than purely individual action. This might be the activities of government or wider society. But what does it mean to think about ‘health’ and the ‘public’ together?

What is ‘public health’?

A classic definition of public health was offered by the American public health expert CEA Winslow in 1920. Winslow stated that:
Public Health is the science and the art of preventing disease, prolonging life, and promoting physical health and efficiency through organized community efforts for the sanitation of the environment, the control of community infections, the education of the individual in principles of personal hygiene, the organization of medical and nursing service for the early diagnosis and preventive treatment of disease, and the development of the social machinery which will ensure to every individual in the community a standard of living adequate for the maintenance of health. 2
Drilling down into this definition in more detail is instructive. Winslow tells us that public health is about ‘preventing disease’, ‘prolonging life’ and ‘promoting physical health’. But he is not just describing what public health is: Winslow also tells us how this could be achieved. Public health can be brought about through ‘organized community efforts’. For this we need medical and nursing services, but also ‘the development of social machinery’ to guarantee everyone ‘a standard of living adequate for the maintenance of health’. What Winslow is proposing is a set of actions, services and broader collective efforts to generate good public health.

Change and continuity over time

What you may also have noticed about Winslow’s definition is his emphasis on sanitation, control of community infections, and education about personal hygiene. This tells us something about the challenges that public health faced at the time. Indeed, if we look at a more recent definition of the meaning of public health, we can observe some changes. In 1988, the Chief Medical Officer, Donald Acheson, defined public health as ‘the science and art of preventing disease, prolonging life and promoting health through organised efforts of society.’ You may recognise elements of this definition in the one produced by Winslow almost 70 years previously. But Acheson also went on to say that:
In the past, “public health” has commonly, if mistakenly, been rather narrowly interpreted and associated in particular with sanitary hygiene and epidemic disease control. We prefer our broader definition…[which] give[s] as much weight to the importance of lifestyle as to environmental hygiene in the preservation and promotion of health. 3
What Acheson is hinting at is that public health can in part be defined by the challenges it faced, a theme we will return to in Step 1.7. His emphasis on lifestyle also suggests a role for individuals in guaranteeing public health, an issue we will look it in more detail in Step 1.12.
So where does this leave us? We can agree that public health is about collective action to benefit the health of the public, but the way in which this is achieved, and the main problems that public health faces, change over time. Let’s now look at these two elements – structures and challenges – in more depth.
© London School of Hygiene & Tropical Medicine
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A History of Public Health in Post-War Britain

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