Health is usually defined as the absence of disease in a given life cycle. The traditional concept of health is "health without disease", but from the perspective of health economics, the modern concept of health is overall health.
For the classic explanation of overall health, the definition of health in the Magna Carta of World Health of the United Nations World Health Organization (WHO) 1974 is the first one: "Health is not just the absence of diseases in the body, but a complete physical, psychological and social adaptability". The World Health Organization puts forward that "health is not only the absence of physical diseases, but also mental health, good social adaptation and morality".