Health Science is the art of preventing disease, increasing longevity of life and promoting health through efforts and choices made by society, public and private organizations, the community and by individuals. Health Science deals with dangers to the public health of a population, whether small or large (i.e. populations of a continent) to improve the quality of health and the quality of life in through detecting and preventing disease and other physical and mental health conditions, promoting health behaviors, tracking cases and health indicators. Health Science uses a multi-disciplinary method incorporating epidemiology, biostatistics and health services. Health sciences are examined in this book.