In a study of American seniors hospitalized with a primary diagnosis of dehydration, the mortality rate in the following year was nearly 50%. This study also found that even when dehydration was not the primary diagnosis, concomitant dehydration increased patients’ relative 12-month mortality risk by 16 to 78%, compared to patients with the same diagnosis but without dehydration (Warren et al. 1994).In older adults with many comorbidities, dehydration can precipitate emergency hospitalization and increase the risk of repeated hospitalizations


What is Dehydration
Although there is no absolute definition, dehydration is typically defined as depletion in total body water content due to fluid losses, diminished fluid intake, or a combination of both. Depending on the ratio between sodium and water losses, dehydration can be classified as isotonic (equal loss in sodium and water – example: diarrhoea), hypertonic (excess loss of water compared to sodium – example: fever) or hypotonic (excess loss of sodium compared to water – example: overuse of diuretics)
Water-loss While Aging
As one ages, the total body water content declines, due to a decrease in lean body mass and an increase in percentage of body fat (a tissue poor in water) (Sheehy et al. 1999). Four to six liters of total body water can be lost from the age 20 to the age of 80