Aging.

Aging, a wearing-out process which affects everything inanimate and animate, is accelerated by abuse of decelerated by care. The psychologic reaction of aging persons vary considerably. The concept of growing older is much more satisfactory and pleasant than the concept of being old, since the former is applicable to everyone regardless of age whereas the latter carries a finite significance as deterioration progresses. Chronologic age is much less important than biologic age. The desideratum is not longevity but rather a long, useful and meaningful life. Although heredity is of importance in longevity, it is a factor over which at present we have no control. However, we can influence the aging process according to whether we care for or abuse the body. The principal factors in accelerated aging, in order of importance, are: 1) tobacco use (particularly cigarette smoking), 2) lack of exercise, and 3) obesity. Conversely, abstinence from tobacco, exercise within tolerance, and avoidance of obesity not only decelerate aging but result in a better quality of life.