The term was partly inspired by the preamble to the World Health Organization’s 1948 constitution which said: “Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.” It was initially brought to use in the US by Halbert L. Dunn, M.D. in the 1950s; Dunn was the chief of the National Office of Vital Statistics and discussed “high-level wellness,” which he defined as “an integrated method of functioning, which is oriented toward maximizing the potential of which the individual is capable.” The term “wellness” was then adopted by John Travis who opened a “Wellness Resource Center” in Mill Valley, California in the mid-1970s, which was seen by mainstream culture as part of the hedonistic culture of Northern California at that time and typical of the Me generation. Travis marketed the centre as alternative medicine, opposed to what he said was the disease-oriented approach of medicine. The concept was further popularized by Robert Rodale through Prevention magazine, Bill Hetler, a doctor at the University of Wisconsin–Stevens Point, who set up an annual academic conference on wellness, and Tom Dickey, who established the Berkeley Wellness Letter in the 1980s.
The term had become accepted as standard usage in the 1990s.
In recent decades, it was noted that mainstream news sources had begun to devote more page space to “health and wellness themes”.
The US Substance Abuse and Mental Health Services Administration uses the concept of wellness in its programs, defining it as having eight aspects: emotional, environmental, financial, intellectual, occupational, physical, social, and spiritual.
Source :- Wikipedia