Novadays the perc entage of the population identified as elderly is increasing at an astonishing rate. Because of improved medical care, better nutrition and an emphasis on exercise, an ever-growing number of people are living to age 65 and older. With this increase, it will become increasingly important for clinical laboratorians to be knowledgable of the aging process and its effects on laboratory values.

There are many biochemical and pyhsiological changes associated with aging. Aging is generally associated with a decreasing efficiency in adaptation to stress, reduction in muscle mass and a gradual decline in respiratory, cardiovascular, kidney, liver, immun, neurologic and endocrine system functions. Furthermore, there is extensive individuality among people in regard to the rate at which aging occurs. Environmental and social factors are also important for the initiation and development of aging process.