Health science is the branch of science focused on health. There are two main approaches to health science: the study and research of the body and health-related issues to understand how humans (and animals) function, and the application of that knowledge to improve health and to prevent and cure diseases and other physical and mental impairments. The science builds on many sub-fields, including biology, biochemistry, physics, epidemiology, pharmacology, medical sociology. Applied health sciences endeavor to better understand and improve human health through applications in areas such as health education, biomedical engineering, biotechnology and public health.
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.