The most widely accepted definition of good health is that of the World Health Organization Constitution. It states: "health is a state of complete physical, mental and social well-being and is not merely the absence of disease or infirmity" (World Health Organization, 1946). In more recent years, this statement has been amplified to include the ability to lead a "socially and economically productive life".
The WHO definition is not without criticism mainly that it is much too broad.The most solid aspects of wellness that fit firmly in the realm of medicine are environmental health, nutrition, disease prevention, and public health. These matters can be investigated at length and can assist in measuring well-being.