Some changes of aging.

Aging is associated with changes in body composition and physiologic function which are important in altering the response to drugs of elderly individuals frequently requiring changes in dosages. Declining abilities to do work can lead to incapacity in the late '70s. Such incapacity can be reduced by reconditioning but is likely to be exacerbated by the deconditioning associated with acute illnesses or surgery. Changes in autonomic function, particularly orthostatic hypotension and bladder atony, are likely causes of disability in the postoperative period. The major increase in mortality in the elderly in the postoperative period is related to co-morbidity rather than physiologic changes. Healthy elderly individuals can be excellent surgical risks with careful management. Those with co-morbid conditions can have their surgical risk substantially reduced by medical management.