Aging is a normal developmental process during which physiological and psychosocial changes occur. Wide variation in the aging process exists among individuals as a result of varied environmental exposures, social relationships, genetic endowment, and health status. Whereas maximum lifespan (the age reached by the longest-lived survivors) for humans is 114 to 120 years, the average human lifespan is approximately 75 years. Developmental changes and adaptations continue throughout aging until death.

The lifespan is divided into phases, with the commonly used periods for these phases being infancy (birth to 1 year), early childhood (1 to 6 years), late childhood (7 to 10 years), adolescence (11 to 18 years), young adulthood (19 to 35 years), early middle age (36 to 49 years), late middle age (50 to 64 years), young-old (65 to 74 years), old (75 to 85 years), and old-old (86 years and older). The group of people who are aged 85 years or older is the most rapidly growing segment of the older population (Fig. 9-1). People in this age group typically have a noticeable decline in functional ability and have one or more chronic disorders.

Aging is a multifactorial process with genetic and environmental components. Each system in an organism, each tissue in a system, and each cell type in a tissue appear to have its own trajectory of aging.¹ Theories of the biologic aspects of aging have been developed and studied.² The theories can be divided into three groups: organ theories, physiological theories, and genome-based theories. The organ theories examine age changes in the body brought about by the possible initiation from a “master” organ system, such as the immune or neurological system. The physiologic theories analyze cell functioning as related to waste product accumulation or molecular changes. The genome-based theories attribute age changes to the individual’s genetic endowment and suggest that a predetermined series of events programmed into cells or random mutations or cell errors are responsible for the process of aging. Probably no one theory can totally explain the aging process, but some or all of these theories may be involved in the complete explanation.

The nurse needs to be aware of several concepts in addressing the health care needs of older adults.

Although Americans are living longer, they are not necessarily healthier. With increasing age, they are at increased risk for illness. Chronic illnesses, such as arthritis, cardiac and vascular problems, and diabetes, are the major health problems of older people (Fig. 9-2). Chronic illnesses do not occur in isolation; 80% of older Americans have one chronic illness and 50% have two or more. Because of the lifestyle changes in young and middle-aged adults, particularly in the areas of diet and exercise, in the near future, older adults may be sufficiently healthier that definitions and expectations of the aging process may need to be revised. At present, however, heart disease and stroke are the first and third leading cause of death of older adults (Fig. 9-3).

When older people become ill, there is frequently an atypical presentation, such as missing or altered symptoms. Confusion is often one of the earliest indications of a change in health status. Restlessness, confusion, or altered mentation often occur in the presence of illness and should not be confused with dementia, providing that dementia was not present before the illness. Acute onset or unexplained deterioration of health should be carefully evaluated and not accepted as a normal concomitant of aging.

The older person who is ill has many adjustments and adaptations to make. The social supports (family and friends) available to that person may be fewer or less able to be supportive because of their own debilities, such as a spouse who is also ill or an adult child who has other responsibilities. Apprehension, worry, and fear of becoming dependent and helpless may add to the emotional burden of the current illness. Of those older adults between 80 and 84 years of age, 30% require assistance with daily activities, and of those adults who are 85 years and older, 50% require assistance.

Older patients require careful, thorough nursing management during an acute illness and afterward. Discharge planning that begins with the admission process and includes consideration of living arrangements, care providers, and support services is especially important for older patients, who are often adversely affected by the shorter hospitalizations and fewer home nursing care visits that accompany changes in managed care.