Understanding Aging and the Elderly Population

The world’s population is aging at an unprecedented pace, with people living longer than ever before. By 2030, one in six people globally will be aged 60 years or over, creating both opportunities and challenges for individuals, families, and healthcare systems.

Table of contents

• Defining Who is Elderly
• The Growing Elderly Population
• Understanding the Aging Process
• Common Health Conditions in Older Age
• Challenges in Caring for Older Adults

Defining Who is Elderly

The definition of who is considered elderly varies across different contexts. Traditionally, age 65 has been used as the starting point for older age, but this designation has historical rather than biological roots^[1]. Many years ago, age 65 was chosen as the retirement age in Germany, the first nation to establish a retirement program^[2]. In the United States, this age was later designated as the eligibility age for Medicare insurance in 1965^[3].

However, the concept of being “elderly” can be understood in several different ways. Chronologic age is simply a person’s age in years based on the passage of time. While this has limited significance in terms of actual health, it does help predict many health problems and has legal and financial uses^[3]. Biologic age refers to the actual physical changes that occur in the body as people age. Because these changes affect people at different rates, some individuals may be biologically older at 65, while others may not reach this state until a decade or more later^[3]. Psychologic age is based on how people act and feel. For example, an 80-year-old who works, plans for the future, and participates in many activities is considered psychologically younger^[3].

Most healthy and active people do not need specialized geriatric care until they are 70, 75, or even 80 years old, though some may need such care earlier due to medical conditions^[3].

The Growing Elderly Population

The world is experiencing a dramatic demographic shift. People worldwide are living longer, and today most people can expect to live into their sixties and beyond^[1]. Every country in the world is experiencing growth in both the size and the proportion of older persons in the population^[1].

By 2030, one in six people in the world will be aged 60 years or over. At this time, the share of the population aged 60 years and over will increase from 1 billion in 2020 to 1.4 billion^[1]. By 2050, the world’s population of people aged 60 years and older will double to 2.1 billion. The number of persons aged 80 years or older is expected to triple between 2020 and 2050 to reach 426 million^[1].

While this shift in distribution toward older ages—known as population ageing—started in high-income countries, it is now low- and middle-income countries that are experiencing the greatest change. In Japan, for example, 30 percent of the population is already over 60 years old. By 2050, two-thirds of the world’s population over 60 years will live in low- and middle-income countries^[1]. In 2050, 80 percent of older people will be living in low- and middle-income countries^[1].

In the United States specifically, the number of Americans ages 65 or older is projected to increase from 58 million (17 percent of the population) in 2022 to 73 million (21 percent of the population) by 2030^[12]. In 2020, the number of people aged 60 years and older outnumbered children younger than 5 years for the first time^[1].

Understanding the Aging Process

At the biological level, aging results from the impact of the accumulation of a wide variety of molecular and cellular damage over time. This leads to a gradual decrease in physical and mental capacity, a growing risk of disease, and ultimately death^[1]. These changes are neither linear nor consistent, and they are only loosely associated with a person’s age in years^[1].

Aging is a gradual, continuous process of natural change that begins in early adulthood. During early middle age, many bodily functions begin to gradually decline^[3]. Some changes that occur with aging are considered normal—sometimes called “pure aging”—because they occur in everyone who lives long enough. These changes are to be expected and are generally unavoidable^[3].

For example, as people age, the lens of the eye thickens, stiffens, and becomes less able to focus on close objects, a condition called presbyopia. This change occurs in virtually all older adults, making it a normal part of aging^[3].

The diversity seen in older age is not random. Beyond biological changes, aging is often associated with other life transitions such as retirement, relocation to more appropriate housing, and the death of friends and partners^[1].

Common Health Conditions in Older Age

Common conditions in older age include hearing loss, cataracts and refractive errors, back and neck pain and osteoarthritis, chronic obstructive pulmonary disease, diabetes, depression, and dementia^[1]. As people age, they are more likely to experience several conditions at the same time^[1].

Most older adults in the United States have at least one chronic health condition^[7]. The elderly population experiences more chronic conditions and comorbidities—which means having multiple health problems at the same time—including degenerative diseases, physical disabilities, and mental illnesses, than younger populations^[15].

It is important to understand that not all health problems are a normal part of aging. For example, with advanced age, a mild decline in mental function is nearly universal and is considered normal aging. This decline includes increased difficulty learning new things such as languages, decreased attention span, and increased forgetfulness. However, the decline that occurs in dementia is much more severe. People who are aging normally may misplace things or forget details, but people who have dementia forget entire events and have difficulty doing normal daily tasks such as driving, cooking, and handling finances^[3].

Older adults are also at higher risk for fall-related injuries. In fact, one in four older adults falls each year, and falls are a leading cause of injury for this age group^[7]. Additionally, older adults are more likely to require hospitalization for some infectious diseases, including pneumonia, which is a leading cause of death for this age group^[7].

Challenges in Caring for Older Adults

All countries face major challenges to ensure that their health and social systems are ready to make the most of this demographic shift^[1]. The pace of population aging is much faster than in the past^[1].

Due to the demographic shift, complex care management of older adults with multiple health problems and changing functional capacities has become core clinical business for many stakeholders in healthcare systems^[14]. There is increased demand for specialty care for this population, as well as a need to address the challenges faced by many older adults—and often their family caregivers—in accessing affordable, high-quality care^[15].

An aging population means higher use of healthcare services and a greater need for family and professional caregivers^[16]. Occupations related to elder care are some of the fastest-growing occupations in the United States. For example, the number of nurse practitioners is expected to grow 44.5 percent from 2022 to 2032, and home health and personal care aides are expected to grow 21.7 percent^[12].

Caring for elderly parents or relatives involves tremendous responsibility and can cause overwhelming pressure. Family members may face profound emotional, physical, and mental challenges^[21]. Around 37 million people in the United States, or 14 percent of the population, provided unpaid eldercare during 2021 and 2022. Over a quarter of them provide unpaid eldercare on any given day, spending an average of 3.6 hours per day^[12].

Financial challenges are also significant. For nursing homes in particular, costs can be substantial. A private room in a nursing home averages $8,121 per month^[11]. Nearly one in ten older adults lives in poverty^[16].