Health

"Health is the level of functional and metabolic efficiency of a living organism. The definition of health has evolved over time. In keeping with the biomedical perspective, early definitions of health focused on the theme of the body's ability to function; health was seen as a state of normal function that could be disrupted from time to time by disease. Then, in 1948, in a radical departure from previous definitions, the World Health Organization (WHO) proposed a definition that linked health to well-being, in terms of 'physical, mental, and social well-being, and not merely the absence of disease and infirmity'."
-- Wikipedia