Story: Public health

Page 1. What is public health?

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Public health means health and medical initiatives that focus on:

  • the prevention of disease
  • the promotion of good health
  • the health of whole populations rather than individuals
  • the identification and elimination of health inequalities.

The substantial improvements in health since the 19th century have been largely attributed to public health initiatives to prevent and control diseases rather than to medical interventions to treat individual patients – prevention has often been more effective than cure.

The term ‘public health’ is sometimes used by lay people to describe health services that are funded by the government through taxation – the public health system. This can cause confusion.

Public health practitioners

People who work in public health tend to concentrate on the impact of health factors and interventions on communities and populations. In contrast, health professionals and clinicians focus on individual patient care in clinics and hospitals.

Public health practitioners include doctors, nurses, health promotion specialists, and advocates. Given the broad scope of public health, many people who may not call themselves public health practitioners perform activities that affect the health of the population and help address public health issues. Examples include teachers, politicians, town planners, sports coaches and administrators.

Old and new models of public health practice 

Public health practice originated in a world where the primary causes of avoidable ill health and premature death were infectious diseases resulting from poor housing, air pollution and inadequate clean water supplies and sanitation. As a result, public health practice was primarily concerned with improving sanitation and hygiene, and later, providing clean water and air.

With the success of early public health measures, infectious disease mortality diminished. The major causes of poor health increasingly became chronic diseases like heart disease, stroke and cancer. A new model of public health arose in the second half of the twentieth century to address the causes of these chronic diseases, including smoking, poor diet and excessive alcohol intake. 

Public health practitioners identified that infectious and chronic diseases disproportionately affected poorer and more disadvantaged sections of society. More consideration was given to social, cultural, environmental and political factors as determinants of health. Reducing or eliminating these health inequalities has been an important focus for public health. In New Zealand there has been a particular focus on disparities by ethnicity, particularly for Māori.

Infection control remained important in the early 21st century. This was especially the case for the ‘swine flu’ (2009) and COVID-19 coronavirus (2020) pandemics. Stringent border controls were introduced to limit the spread of the latter virus.

How to cite this page:

Kerryn Pollock, 'Public health - What is public health?', Te Ara - the Encyclopedia of New Zealand, (accessed 22 June 2024)

Story by Kerryn Pollock, published 5 May 2011, reviewed & revised 7 Jul 2019 with assistance from Richard Edwards