Rosa, the immigrant from Mexico, is typical of older adults: She is beginning to experience some recur­ring health difficulties and finding out that she does not recover as quickly from even minor afflictions. You probably have had several encounters with ill­nesses that come on quickly, may range from mild to very severe, last a few days, and then go away. Illnesses such as influenza and strep throat are examples. You also may have experienced condi­tions that come on more slowly, last much longer, and have long-term consequences. Kidney disease, diabetes, and arthritis are examples. Your expe­riences reflect the difference between acute and chronic diseases.

Acute diseases are conditions that develop over a short period of time and cause a rapid change in health. We are all familiar with acute diseases, such as colds, influenza, and food poisoning. Most acute diseases are cured with medications (such as anti­biotics for bacterial infections) or allowed to run their course (the case with most viral infections). In contrast, chronic diseases are conditions that last a longer period of time (at least 3 months) and may be accompanied by residual functional impairment

that necessitates long-term management. Chronic diseases include arthritis and diabetes mellitus.

What do you think happens to the incidence of acute and chronic diseases as people age? If you say that the rates of acute diseases go down whereas the rates of chronic diseases go up, you are cor­rect. Contrary to what many people believe, older adults have fewer colds, for example, than younger adults. However, when they do get an acute dis­ease, older adults tend to get sicker; recovery takes longer and death from acute disease occurs more often (National Center for Health Statistics, 2008b). Thus, although they get fewer acute infections, older people may actually spend more days feeling sick than their younger (and, based on frequency of occurrence, “sicker”) counterparts.

This is probably why many people mistakenly believe that the rates of acute disease increase with age. Because they have more problems fighting acute infections, older adults are more at risk from dying of an acute condition. For example, the rate of respiratory infection is about the same for younger and older adults, but people over age 65 account for roughly 90% of deaths from pneumonia and influenza. For these reasons, health professionals strongly recommend that older adults be vacci­nated against pneumonia and influenza; these shots reduce the risk of pneumonia by about two thirds and influenza by half (Centers for Disease Control and Prevention, 2008f).

Until the 1990s, chronic disease was simply viewed as a part of aging. With the publication in 1991 of the historic document Healthy People 2000: National Health Promotion and Disease Prevention (U. S. Department of Health and Human Services,

1991) , the view shifted dramatically to one of pre­vention and wellness. As we see a bit later in this chapter, advances in managing chronic conditions have been made.