The generally accepted definition of health is "a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity", used by the World Health Organization (WHO) since 1948. 1 Preamble to the Constitution of the World Health Organization as adopted by the International Health Conference, New York, 19-22 June, 1946; signed on 22 July 1947 by the representatives of 61 States (Official Records of the World Health Organization, no. 2, p. 100); and entered into force on 7 April 1948.2 Constitution of the World Health Organization- Basic Documents, Forty-fifth edition, Supplement, October 2006.

In 1986, the WHO in the Ottawa Charter for Health Promotion said health is "a resource for everyday life, not the objective of living. Health is a positive concept emphasizing social and personal resources, as well as physical capacities". Classification systems such as the WHO Family of International Classifications (WHO-FIC), which is composed of the International Classification of Functioning, Disability, and Health (ICF) and the International Classification of Diseases (ICD) also define health.

Overall health is achieved through a combination of physical, mental, emotional, and social well-being.

Physical health

Physical fitness refers to good body health, and is the result of regular exercise, proper diet and nutrition, and proper rest for physical recovery.

A strong indicator of the health of localized population is their height or weight, which generally increases with improved nutrition and health care. This is also influenced by the standard of living and quality of life. Genetics also plays a major role in people's height. The study of human growth, its regulators, and implications is known as Auxology.

Mental health

Mental health refers to an individual's emotional and psychological well-being. "A state of emotional and psychological well-being in which an individual is able to use his or her cognitive and emotional capabilities, function in society, and meet the ordinary demands of everyday life."

One way to think about mental health is by looking at how effectively and successfully a person functions. Feeling capable and competent; being able to handle normal levels of stress, maintain satisfying relationships, and lead an independent life; and being able to "bounce back," or recover from difficult situations, are all signs of mental health. The generally accepted definition of health is "a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity", used by the World Health Organization (WHO) since 1948. 34

In 1986, the WHO in the Ottawa Charter for Health Promotion said health is "a resource for everyday life, not the objective of living. Health is a positive concept emphasizing social and personal resources, as well as physical capacities". Classification systems such as the WHO Family of International Classifications (WHO-FIC), which is composed of the International Classification of Functioning, Disability, and Health (ICF) and the International Classification of Diseases (ICD) also define health.