Disease Presentation

Much was learned in the twentieth century about disease and how it presents in children and adults. Traditional medical teaching emphasizes specific disease symptoms and signs that point to a specific diagnosis. However, in the last several decades it has become apparent that common diseases often present differently in older adults. This has lead to the concept of so-called atypical disease presentation in older adults. The exact prevalence of atypical disease presentation in the elderly is unclear in the medical literature but some researchers report that as many as 50 percent or more of older adults, particularly those who are frail, primarily present with disease atypically.

As people age, many bodily changes occur, but two have major consequences for disease presentation. The first is the inevitable alterations that occur within the various body systems that represent normal physiological changes of aging. Many are unavoidable and alone do not fully explain why older adults often present atypically. However, some of these changes certainly set the stage for increased susceptibility both to illness and to the way in which the disease presents itself. A classic example is alteration in thermoregulation with age, so that many older people do not have a fever when infected. Other examples are the increased risk for hyperthermia, hypothermia as well as dehydration due primarily to the changes in the body's ability to control body temperature and detect thirst. These normal consequences of aging coupled with concomitant disease and medications often together help set the stage for atypical disease presentations.

The second change that occurs with aging is related to the pathophysiological changes associated with aging, or the accumulation of disease. Many of the most common diseases that affect people increase in frequency and severity as the body ages. The likelihood of developing major diseases such as heart disease, diabetes, osteoporosis, stroke, and dementia all increase with age.

Another evolving concept that contributes to atypical disease presentations in older adults is the syndrome of frailty, understood as a vulnerable state arising from multiple interacting medical and social problems. The syndrome of frailty is critical to the understanding of disease presentation in the older adult. It is the frail elderly who most often present atypically.