A review of water balance in ageing in health and disease

The elderly are at increased risk of changes in body water and sodium, ofte n accompanying comorbid disease states, which are associated with increased mortality. The clinical assessment of the hydration status of an elderly p atient is difficult and the elderly care physician relies on both the clini cal picture and laboratory investigation. Although sti II contentious, rese arch suggests that the elderly may appreciate thirst less readily. However, healthy elderly may be able to produce an enhanced vasopressin response to osmotic stimulation compared to their younger counterparts, possibly in re sponse to reduced renal function. The changes in these systems, when combin ed with coincident disease, place elderly patients at risk of water imbalan ce and electrolyte disturbance.