AGE-RELATED CHANGES THAT PROMOTE DEHYDRATION
With aging, it becomes more difficult for the body to maintain fluid balance. There are several reasons.The thirst response, which is the body’s primary mechanism of signaling the need for fluid, becomes blunted with age. This was apparent in a 2002 trial that compared men 51 to 60 years of age with those 20 to 28 years of age. During a strenuous 10-day hill-walking excursion, the older men had less thirst and became progressively dehydrated; younger participants had no dehydration.17 An earlier study found that in older men, the serum markers of dehydration (serum osmolality and sodium level) took longer to return to normal after an episode of dehydration than they did in younger men.