Geriatrics refers to medical care for older adults, an age group that is not easy to define precisely. Gerontology is the study of aging, including biologic, sociologic, and psychological changes. “Older” is preferred over "elderly," but both terms are equally imprecise. It is important to avoid terms and attitudes that suggest bias against older adults (ageism). Although there is no set age to define older age, > age 65 is often used because this is the age that determines eligibility for Medicare insurance in the United States. However, some people with medical conditions require geriatrics expertise at a younger age. For example, the Program of All-Inclusive Care for the Elderly (PACE) sets the age for eligibility beginning at 55 for people who meet the need for nursing home level of care.
The percentage of the United States population that was ≥ 65 increased from 5% in 1920 to almost 17% in 2020 (1). Additionally, projections indicate this proportion will continue to increase, with approximately 20% of the United States population expected to be 65 years or older by 2030 (2).
In 2022, life expectancy in the United States for males was 74.8 years and for females was 80.2 years. (3). Within the United States there are also geographic disparities, with life expectancy at age 65 ranging from 16.1 years in Mississippi to 20.6 years in Hawaii (4). Globally, life expectancy in older adults continues to rise worldwide, primarily due to a decrease in tobacco use and decrease in cardiovascular disease mortality (5)
General references
1. United States Census Bureau. 2020 Census: 1 in 6 people in the United States were 65 and over. 2023. Accessed January 23, 2025.
2. Hamidi M, Joseph B. Changing Epidemiology of the American Population. Clin Geriatr Med. 2019;35(1):1-12. doi:10.1016/j.cger.2018.08.001
3. Xu J, Murphy SL, Kochanek KD, et al. Deaths: Final Data for 2022. Natl Vital Stat Rep. 2025;(4):1. doi:10.15620/cdc/174588
4. Arias E, Xu J, Tejada-Vera B, et al. U.S. State Life Tables, 2022. Natl Vital Stat Rep. 2025;(12):1. doi:10.15620/cdc/174620
5. Mathers CD, Stevens GA, Boerma T, et al. Causes of international increases in older age life expectancy. Lancet. 2015;385(9967):540-548. doi:10.1016/S0140-6736(14)60569-9
Aging
Aging (ie, pure aging) refers to the inevitable, irreversible decline in organ function that occurs over time even in the absence of injury, illness, environmental risks, or poor lifestyle choices (eg, unhealthy diet, lack of exercise, substance use disorder). Initially, the changes in organ function (see table ) do not affect baseline function; the first manifestations are a reduced capacity of each organ to maintain homeostasis under stress (eg, illness, injury). The cardiovascular, renal, and central nervous systems are usually the most vulnerable.
Diseases interact with the effects of pure aging to cause geriatric-specific complications, also referred to as geriatric syndromes, which affect organ systems beyond the primary disease target (1). Typical examples are:
Delirium complicating pneumonia or urinary tract infections
The falls, dizziness, syncope, urinary incontinence, and weight loss that often accompany many minor illnesses in older adults
Aging organs are also more susceptible to injury (eg, intracranial hemorrhage is more common and is triggered by less clinically important injury in older adults).
The effects of aging must be taken into account during the diagnosis and treatment of older adults. Clinicians should not:
Mistake pure aging for disease (eg, slow information retrieval is not dementia)
Mistake disease for pure aging (eg, ascribe debilitating arthritis, tremor, or dementia to old age)
Ignore the increased risk of adverse drug effects on weak-link systems stressed by illness
Forget that older adults often have multiple underlying disorders (eg, hypertension, diabetes, atherosclerosis) that accelerate the potential for harm
In addition, clinicians should be alert for diseases and problems that are much more common among older adults (eg, heart failure with reduced ejection fraction, Alzheimer disease, incontinence, atrial fibrillation). This approach enables clinicians to better understand and manage the complexity of the diseases that often coexist in older patients. Understanding the physical changes and geriatric-specific manifestations of disease that accompany advancing age is important to avoid the negative and prejudicial stereotypes about older adults that characterize ageism and can negatively affect patient care and quality of life.
Ageism refers to prejudice against older adults. Similar to other forms of prejudice (eg, racial, ethnic), ageism is based on negative misconceptions and stereotypes and may be conscious or unconscious, overt or subtle. Unlike many other forms of prejudice, ageism is rarely intentionally malicious but nonetheless can cause emotional distress and has adverse practical consequences (eg, being encouraged to retire from work, not being invited to participate in groups or committees). Clinicians effectuate age bias by not offering a treatment to an older adult based simply on their age rather than on factors such as expected functional status, life expectancy, quality of life, and patient preference.
Aging reference
1. Inouye SK, Studenski S, Tinetti ME, et al. Geriatric syndromes: clinical, research, and policy implications of a core geriatric concept. J Am Geriatr Soc. 2007;55(5):780-791. doi:10.1111/j.1532-5415.2007.01156.x
More Information
The following English-language resource may be useful. Please note that The Manual is not responsible for the content of this resource.
