Geriatrics

Geriatrics is the medical specialty concerned with elderly people and the field of human aging. Due to the important and worldwide population aging, geriatrics became an important specialty in medical care and in public health planning. Geriatrics deals with the human aging process and its implications, as well as with the prevention, diagnosis, and treatment of health problems in elderly people.

During human aging, people undergo transformations that change the likelihood of becoming ill, because the functional reserve of one person—the capacity of functioning of each human organ or system surpassing the needs of everyday life—decays in this process. Importantly, however, in the absence of health challenges (e.g., diseases), human aging does not impose restrictions to everyday life.

Since aging is a progressive phenomenon, this likelihood of illness tends to increase with age. As both susceptivity and reaction capacity for diseases change with age, so too do the clinical manifestations of many common diseases. A myocardial infarction may arise without pain in an older person, making the clinical picture very different from what medical doctors might generally expect.

Another specificity of geriatrics is the so-called co-morbidity; because the effects of bad habits (e.g., bad nutrition, smoking, sedentarism, alcohol and abuse of other substances) tend to accumulate with time and the same is true for chronic diseases, it is common for an elderly person to have different diseases at one time. Comorbidities and bad health habits may increase the decay of functional reserve, making an individual more frail than he or she should be at a given age. This is called pathological aging, the phenomenon responsible for making people's health status different from each other's. A geriatrician, therefore, has to be able to give preventive care for anyone concerned with keeping good health, to care for multiple chronic diseases in an elderly person, or even to give palliative care for those dying. That makes geriatrics a very broad field.

Some conditions are common in the elderly and they are studied carefully within geriatrics. They include cognition-affecting diseases (notably Alzheim-er's disease), depression and delirium (a mental disorder arising from clinical diseases), urinary symptoms [Page 732]and diseases (such as urinary incontinence or prostate diseases), malnutrition, immobility, and falls.

While caring for comorbid conditions, geriatrics concentrates on maintaining the functional status of patients, because this is what allows the engagement of daily living activities or prevents a person from doing so rather than the number or importance of the diseases per se. In this sense, rehabilitation (e.g., with physical or occupational therapy) after a loss of health status or adaptations in the environment (e.g., the substitution of a ladder for a slope allowing the passage of wheelchairs) may help a patient recover functional status even when the medical condition responsible for the loss is irreversible.

Polypharmacy is another common situation in geriatric care. Having more than one chronic condition, for example, diabetes, hypertension, and high low-density lipoprotein (LDL) cholesterol levels, may imply the need for simultaneous treatments, frequently with the use of multiple drugs, increasing the chances of adverse or antagonistic drug effects. The simultaneous use of different drugs may also be a burden in the patient's metabolism, because the metabolic reserve also diminishes with age. Finally, changes in the metabolism and body composition result in several pharmacological behaviors different of those observed in young adults. A common condition is related to the duration and intensity of a drug effect: lipid-soluble drugs tend to have longer-lasting effects in the elderly and water-soluble drugs tend to have more intense effects due to the fat increasing with aging at the same time that the proportion of water decreases.

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