defination public health

Public Health

Public health refers to “the science and art of preventing disease, prolonging life and promoting health through organized efforts and informed choices of society, organizations, public and private, communities and individuals.” 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 (for instance, in the case of a pandemic).

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. Public health incorporates the interdisciplinary approaches of epidemiology, biostatistics and health services.

Environmental health, community health, behavioral health, health economics, public policy, insurance medicine, mental health and occupational safety and health are other important subfields.

Definition of Public Health

Public health is defined as the science of protecting the safety and improving the health of communities through education, policy making and research for disease and injury prevention.

The definition of public health is different for every person. Whether you like to crunch numbers, conduct laboratory or field research, formulate policy, or work directly with people to help improve their health, there is a place for you in the field of public health. Being a public health professional enables you to work around the world, address health problems of communities as a whole, and influence policies that affect the health of societies.

Public health involves the application of many different disciplines:


What do public health professionals do?

As a public health professional, you will be trained to perform one or more of these ten essential services:

  • Monitor the health status of a community to identify potential problems
  • maxresdefaultDiagnose and investigate health problems and hazards in the community
  • Inform, educate, and empower people about health issues, particularly the underserved and those at risk
  • Mobilize community partnerships to identify and solve health problems
  • Develop policies and plans that support individual and community health efforts
  • Enforce laws and regulations that protect health and ensure safety
  • Link people to needed personal health services and ensure the provision of health care when otherwise unavailable
  • Ensure a competent public health and personal health care workforce
  • Evaluate effectiveness, accessibility, and quality of personal and population-based health services
  • Research new insights and innovative solutions to health problems

A public health professional specializing in epidemiology might coordinate with community leaders to stop the spread of that very same STD. According to the Center for Disease Control (CDC), the nation’s premier public health agency, the philosophy is simple: find out what’s making people sick and killing them, and then do the things that work to protect them and make them healthier.

During the 20th century, the average lifespan worldwide increased by 30 years. Twenty-five of the years can be attributed directly to advances in public health. These advances fall into three main categories: sexual health, disease and safety.


Safer and Healthier Foods: Contaminated food, milk and water cause many infections, including typhoid fever, tuberculosis, botulism and scarlet fever. Initiatives to ensure safer and healthier foods have resulted in significant decreases in microbial contamination. The discovery of essential nutrients and their roles in disease prevention has been instrumental in reducing nutritional deficiency diseases such as goiter, rickets and pellagra in the United States.

Safer and Healthier Foods

Family Planning: Family planning health includes smaller family size and longer interval between the birth of children; increased opportunities for pre-pregnancy counseling and screening; fewer infant, child and maternal deaths; and the use of barrier contraceptives to prevent pregnancy and transmission of human immunodeficiency virus and other STDs.

healthHealthier Mothers and Babies: From 1915 through1997, the maternal mortality rate declined to less than 0.1 reported deaths per 1,000 live births, and the infant mortality rate fell to 7.2 per 1,000 live births. Environmental interventions, improvements in nutrition, advances in clinical medicine, increased access to health care, better disease surveillance and monitoring, and higher standards of living contributed to these remarkable declines.

Tobacco as a Health Hazard: Smoking is the leading cause of preventable disease in the U.S. Recognition of tobacco use as a health hazard has resulted in restrictions on cigarette advertising, consumer education campaigns and initiatives aimed at reducing the population’s exposure to environmental tobacco smoke.


Immunizations: Since 1900, smallpox was eradicated through vaccinations. Vaccines have been developed or licensed against 21 other diseases, including polio and measles, dramatically reducing the incidence of infections and deaths.

Public HealthDeclines in Death from Heart Disease and Stroke: Heart disease and strokes together account for approximately 40 percent of all deaths in the United States. Since 1950, age-adjusted death rates from cardiovascular disease (CVD) have declined 60 percent, representing one of the most important public health achievements of the 20th century.

Control of Infectious Diseases: Public health action to control infectious diseases in the 20th century were based on the 19th century discovery of microorganisms as the cause of many serious diseases, such as cholera and tuberculosis. Improvements in sanitation and hygiene, the discovery of antibiotics, and the implementation of universal childhood vaccination programs, all contributed to infectious disease control.

Fluoridation of Drinking Water: Fluoridation of community drinking water is a major factor responsible for the decline in tooth decay during the second half of the 20th century. The history of water fluoridation is a classic example of clinical observation leading to epidemiologic investigation and community-based public health intervention.



Public HealthMotor Vehicle Safety: Motor vehicle safety initiatives focus on protecting occupants and educating drivers and pedestrians. Seat belts, child safety seats, public awareness about the dangers of drinking and driving and stricter laws and law enforcement are all results of public health efforts.

Workplace Safety: Public health efforts have led to physical changes in the workplace, such as improved ventilation and dust suppression in mines; safer equipment; development and introduction of safer work practices; and improved training of health and safety professionals and of workers.

While many of these important initiatives are ongoing, the 21st century brings with it new public health challenges. Predominant among these are “diseases of comfort,” such as those caused by obesity and physical inactivity, a major focus of public health today. Many experts agree that major advances in public health improvement over the next decades will come not from new medical findings or cures, but from the development and application of population-based prevention programs.