Elsevier

Disease-a-Month

Volume 61, Issue 11, November 2015, Pages 454-459
Disease-a-Month

What is aging?

https://doi.org/10.1016/j.disamonth.2015.09.002Get rights and content

Introduction

Aging and human development are complex processes that results in a variety of changes to the living organism over time. Aging at the individual level has been defined in many different ways over the years using many of similar characteristics. Arking (1999) proposed the following definition: “the time-independent series of cumulative, progressive, intrinsic, and deleterious functional and structural changes that usually begin to manifest themselves at reproductive maturity and eventually culminate in death.”1 These individual changes become apparent in biological, psychological, and social dimensions, and many theories have been developed to help explain how these processes occur. A selection of these theories will be discussed in detail in the following sections of this issue.

Section snippets

Population aging

Aging has recently been given heightened attention for its societal impacts in many parts of the world. The aging of a society—known as population aging—is associated with rising numbers and proportions of the older population within a society. The process represents a human success story of increased longevity, as improvements in life expectancy and declines in fertility have been among the most dominant global demographic trends in the second half of the 20th century.2 The United States is

Why an aging society matters

Gerontologists tend to use chronological age to divide old age into three subcategories: oldest-old, people who are 85 years of age or older; old–old, people aged 75–84 years; and young–old, people aged 65–74 years.4 In the United States over the last century, particularly since about 1970, improvements in life expectancy have contributed to growth in every age group. The most significant change will be seen in the growth of the oldest-old category, in which the number of people is projected to

Process of aging

Researchers may, depending on the situation, use different markers of age to study the process of aging. Chronological age, though often an arbitrary marker, is commonly used in decision-making around inclusion or eligibility (e.g., at age 65, full Social Security benefits and Medicare can be accessed).4 Functional age is often based on a person’s ability to perform certain functions or roles. For human beings, aging results in increasing loss of function and entropy as homeostatic mechanisms

Overview of issue

The following articles composing this issue will introduce various theories that may be useful to primary care providers for understanding the complex, multifactorial process of aging. Biological theories, such as programmed, free radical, and crosslinking theories, help to explain some of the natural forces that lead to the body’s weakened ability to manage stress and greater susceptibility to illness and death. Social theories, such as activity, disengagement, and continuity theories, help to

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  • Cited by (8)

    • Why we should use topological data analysis in ageing: Towards defining the “topological shape of ageing”

      2020, Mechanisms of Ageing and Development
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      Indeed, presently several hundred theories exist, all of which attempt to define ageing. However, at the current stage, it is unlikely that any of these will explain or ultimately conceptualize ageing (Rose et al., 2012; Lipsky and King (2015); Cannon, 2015; da Costa et al., 2016). Also, there are so many aspects of ageing that none of the existing theories can integrate (and synthesize) them by including molecular, biological, physiological, functional, social, or psychological aspects.

    • A hermeneutic phenomenological explorations of living in old age

      2018, Geriatric Nursing
      Citation Excerpt :

      Furthermore, with age, people may end up internalizing these negative stereotypes, and as a result of these internalizations may actually begin to present signs of, for example, failing memory, cognitive confusion or physical frailty.7 Older people also frequently perceive themselves to be a burden on their families and on society.8,9 It should be noted, however, that there are also salutogenic perspectives10,11 which highlight the positive and enriching aspects of aging.

    • Treatment of Elderly Patients With Aplastic Anemia

      2017, Congenital and Acquired Bone Marrow Failure
    • Are We Ill Because We Age?

      2019, Frontiers in Physiology
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