Public health is the study and practice of managing threats to the health of a community. The field pays special attention to the social context of disease and health, and focuses on improving health through society-wide measures like vaccinations, the fluoridation of drinking water, or through policies like seatbelt and non-smoking laws.
The goal of public health is to improve lives through the prevention and treatment of disease. The United Nations' World Health Organization defines health as "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity." In 1920, C.E.A. Winslow defined public health as "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals."
The public-health approach can be applied to a population of just a handful of people or to the whole human population. Public health is typically divided into epidemiology, biostatistics and health services. Environmental, social, behavioral, and occupational health are also important subfields.
Objectives
The focus of a public health intervention is to prevent rather than treat a disease through surveillance of cases and the promotion of healthy behaviors. In addition to these activities, in many cases treating a disease can be vital to preventing its spread to others, such as during an outbreak of infectious disease or contamination of food or water supplies. Vaccination programs and distribution of condoms are examples of public health measures.
Most countries have their own government public health agencies, sometimes known as ministries of health, to respond to domestic health issues. In the United States, the frontline of public health initiatives are state and local health departments. The United States Public Health Service (PHS), led by the Surgeon General of the United States, and the Centers for Disease Control and Prevention, headquartered in Atlanta and a part of the PHS, are involved with several international health activities, in addition to their national duties.
There is a vast discrepancy in access to healthcare and public health intiatives between developed nations and developing nations. In the developing world, public health infrastructures are still forming. There may not be enough trained health workers or monetary resources to provide even a basic level of medical care and disease prevention. As a result, a large majority of disease and mortality in the developing world results from and contributes to extreme poverty. For example, many African governments spend less than USD$10 per person per year on healthcare, while, in the United States, the federal government spent approximately USD$4,500 per capita in 2000.
Many diseases are preventable through simple, non-medical methods. For example, research has shown that the simple act of hand washing can prevent many contagious diseases.
Public health plays an important role in disease prevention efforts in both the developing world and in developed countries, through local health systems and through international non-governmental organizations, like the International Public Health Forum (IPHF)
The two major postgraduate professional degrees related to this field are the Master of Public Health (MPH) or the (much rarer) Doctor of Public Health (DrPH). Many public health researchers hold PhDs in their fields of speciality, while some public health programs confer the equivalent Doctor of Science degree instead. The United States medical residency specialty is General Preventive Medicine and Public Health.
