The Definition of Health

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In the medical field, health is commonly defined as an organism’s ability to efficiently respond to challenges (stressors) and effectively restore and sustain a “state of balance” known as homeostasis.

Health is the level of functional and/or metabolic efficiency of an organism at both the cellular and social level. The word “health” comes from the Old English word hale, meaning “free from disease or infirmity”.

In humans, it is the general condition of a person in the mind, body and spirit, usually meaning to be free from illness, injury or pain (referred to as “in good health” or “healthy”).

In 1946, the World Health Organization (WHO) defined health in its broader sense as “a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity” [1]. The highest possible attainment of health is a fundamental right of every human being without distinction of any kind.


  1. Grad FP. The Preamble of the Constitution of the World Health Organization. World Health Organization. 1946.
About the Author

Walter Jessen, Ph.D. is a Data Scientist, Digital Biologist, and Knowledge Engineer. His primary focus is to build and support expert systems, including AI (artificial intelligence) and user-generated platforms, and to identify and develop methods to capture, organize, integrate, and make accessible company knowledge. His research interests include disease biology modeling and biomarker identification. He is also a Principal at Highlight Health Media, which publishes Highlight HEALTH, and lead writer at Highlight HEALTH.