Age-associated diseases and conditions: implications for decreasing late life morbidity.

We discuss two types of age-associated diseases; aging-dependent such as Alzheimer's disease and congestive heart failure which increase logarithmically with age, versus age-dependent such as multiple sclerosis and amyotrophic lateral sclerosis which occur at proscribed ages, and then occurrence of new cases ceases or diminishes with further aging. Prevention strategies with both types emphasize postponement or delay of onset. The non-fatal aging-dependent diseases and conditions are an accumulating burden as we age, and increase overall morbidity in late years. These include Alzheimer's disease and other dementias, Parkinson's disease, loss of vision and hearing, incontinence, osteoporosis and hip fracture, osteoarthritis and depression. With mortality postponed, we will be living for many years at old and vulnerable ages. Life's quality will be reasonable for most. Still, increasing the chance that all will experience this desirable outcome requires pursuing the means to delay the onset of the physical and social events which we categorize as the non-fatal aging-dependent diseases and conditions. We must recognize that each added year occurs at the tip of an exponential curve where risk is maximal.