Public health has been described 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." It is concerned with threats to the overall health of a community 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). Public health has many sub-fields, but typically includes the interdisciplinary categories of epidemiology, biostatistics and health services. Environmental health, community health, behavioral health, and occupational health are also important areas of public health.
1. hale, hearty, robust. 3. nutritious, nourishing. Healthy, healthful, salutary, wholesome refer to the promotion of health. Healthy, while applied especially to what possesses health, is also applicable to what is conducive to health: a healthy climate; not a healthy place to be. Healthful is applied chiefly to what is conducive to health: healthful diet or exercise. Salutary suggests something that is conducive to well-being generally, as well as beneficial in preserving or in restoring health: salutary effects; to take salutary measures. It is used also to indicate moral benefit: to have a salutary fear of devious behavior. Wholesome has connotations of attractive freshness and purity; it applies to what is good for one, physically, morally, or both: wholesome food; wholesome influences or advice.
In 2005, the Supreme Court of Canada ruled, in Chaoulli v. Quebec, that the province's prohibition on private insurance for health care already insured by the provincial plan violated the Quebec Charter of Rights and Freedoms, and in particular the sections dealing with the right to life and security, if there were unacceptably long wait times for treatment, as was alleged in this case. The ruling has not changed the overall pattern of health insurance across Canada, but has spurred on attempts to tackle the core issues of supply and demand and the impact of wait times.