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Geriatrics refers to medical care for the elderly, an age group that is not easy to define precisely; “older people” is sometimes preferred but is equally imprecise. Gerontology is the study of aging, including biologic, sociologic, and psychologic changes.

Most age-related biologic functions peak before age 30 and gradually decline linearly thereafter (see Table 1: Geriatric Medicine: Selected Physiologic Age-Related Changes ); the decline may be critical during stress, but it generally has little or no effect on daily activities. Therefore, disorders, rather than normal aging, are the primary cause of functional loss during old age. Also, in many cases, the declines that occur with aging may be due at least partly to lifestyle, behavior, diet, or environment and thus can be modified. For example, aerobic exercise can prevent or partially reverse declines in maximal exercise capacity (O₂ consumption per unit time, or Vo₂max), muscle strength, and glucose tolerance in healthy but sedentary older people. The unmodifiable effects of aging may be less dramatic than thought, and healthier, more vigorous aging may be possible for many people.

Table 1
Selected Physiologic Age-Related Changes  This table is presented as a PDF and requires the free Adobe PDF reader. Get Adobe Reader

Demographics: Around 1900 in the US, people > 65 accounted for 4% of the population; now, they account for > 13% (37 million, with a net gain of > 1000/day). In 2026, when post–World War II baby boomers begin to reach age 80, estimates suggest that > 20% (almost 80 million) will be > 65. The mean age of those > 65 is now a little over 75, and the proportion of those > 85 is predicted to continue to increase.

For men, life expectancy is 16 yr at age 65 and 9 yr at age 75. For women, life expectancy is 19 yr at age 65 and 12 yr at age 75. Overall, women live about 5 yr longer than men, probably because of genetic, biologic, and environmental factors. These differences in survival have not changed, despite changes in women's lifestyle (eg, increased smoking, increased stress). Maximum human life span (estimated at 110 to 120 yr) has increased modestly compared with the substantial increase in average life expectancy during this century but continues to increase without slowing of the rate. People > 65 are in better health than their predecessors and remain healthier longer. Because of these improvements in health, decline tends to be most dramatic in the oldest old.

Approach to the elderly patient: The elderly have different, often more complicated, health care needs. On average, an elderly patient has 6 diagnosable disorders, and the primary care physician is often unaware of some of them. A disorder in one organ system can weaken another system, exacerbating the deterioration of both and leading to disability, dependence, and, without intervention, death. Multiple disorders complicate diagnosis and treatment, and the effects of the disorders are magnified by social disadvantage (eg, isolation) and poverty (as patients outlive their resources and supportive peers).

Certain common geriatric symptoms (eg, dizziness, syncope, falling, mobility problems, weight or appetite loss) require particular attention because they may result from disorders of multiple organ systems. Also, physicians should use the history, physical examination, and simple laboratory tests to actively screen elderly patients for disorders that occur only or commonly in the elderly (see Table 2: Geriatric Medicine: Disorders Common Among the Elderly); many of these disorders are often missed and can be more easily treated when diagnosed early. Common treatable disorders include vitamin B₁₂ deficiency, iron deficiency anemia, hypothyroidism, heart failure, GI bleeding, diabetes mellitus, foot disorders interfering with mobility, oral disorders interfering with eating, hearing and vision abnormalities, dementia, and depression. In the elderly, these disorders are often diagnosed late or missed or, if noticed, may be erroneously attributed to aging. Prescription and OTC drug use should be reviewed frequently, particularly for drug interactions and use of drugs considered inappropriate for the elderly (see Drug Therapy in the Elderly); computer-based management is more efficient when multiple drugs are used. Early detection of disorders or potential drug interactions results in early intervention, which can prevent deterioration and improve quality of life often through relatively minor, inexpensive interventions (eg, lifestyle changes).

Table 2
Disorders Common Among the Elderly Frequency Disorders Almost exclusive in the elderly Accidental hypothermia Normal-pressure hydrocephalus Urinary incontinence More common in the elderly than among other age groups Basal cell carcinoma Chronic lymphocytic leukemia Degenerative osteoarthritis Dementia Diabetic hyperosmolar nonketotic coma Falls Herpes zoster Hip fracture Monoclonal gammopathies Osteoporosis Parkinsonism Polymyalgia rheumatica Pressure ulcers Prostate cancer Stroke Temporal arteritis (giant cell arteritis)

Caring for elderly patients with multiple disorders requires good diagnostic, analytic, and interpersonal skills. Often, early diagnosis depends on the clinician's familiarity with the patient's behavior and history, including mental status. Commonly, the first signs of a physical disorder, often at a treatable stage, are mental or emotional. If clinicians are unaware of this possibility and attribute these signs to dementia, diagnosis and treatment can be delayed.

If patients have multiple disorders, treatments (eg, bed rest, surgery, drugs) must be well integrated and monitored to avoid iatrogenic consequences. With complete bed rest, elderly patients can lose 5 to 6% of muscle mass and strength each day (sarcopenia), and the effects of bed rest alone can ultimately result in death. Treating one disorder without treating associated disorders may accelerate decline.

Interdisciplinary care: For the above reasons, many elderly patients require interdisciplinary care—coordinated care, typically by physicians, nurses, pharmacists, and sometimes dietitians, physical and occupational therapists, and social workers. For the oldest patients and those with complex conditions, care is usually best managed by a geriatrician. Occasionally, an ethicist or hospice physician is needed. Interdisciplinary care aims to ensure that patients move safely and easily from one place of care to another and from one health care practitioner to another. It also aims to ensure that the most qualified health care practitioner provides care for each problem and that care is not duplicated. Interdisciplinary care is not available everywhere.

Last full review/revision November 2005

Content last modified November 2005