Health can be defined negatively, as the absence of illness, functionally as the ability to cope with everyday activities, or positively, as fitness and well-being (Blaxter 1990).
In any organism, health is a form of homeostasis. This is a state of balance, with inputs and outputs of energy and matter in equilibrium (allowing for growth). Health also implies good prospects for continued survival. In sentient creatures such as humans, health is a broader concept.
The World Health Organization defines health as "a state of complete physical, mental and social well-being, and does not consist only of the absence of disease or infirmity." Though this is a useful and accurate definition, some would consider it idealistic and non-realistic. Using the WHO definition classifies 70-95% of people as unhealthy.
The most solid aspects of wellness that fit firmly in the realm of medicine are the environmental health, nutrition, disease prevention , and public health matters that can be investigated and assist in measuring well-being.
Health is a state of well-being, of being hale or whole. Individual health is founded on a healthy (whole) family, healthy(whole) community and healthy(whole) society within a healthy(whole) world. As it is recognised that the health of a single cell in a person depends on the total health of the person so it is with the individual in society. Few examples of such healthy societies exist in today's world, usually they are isolated like the Hunzas of northern india.
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