Chronic dehydration in older adults: An underestimated health hazard.

Abstract: In contrast to acute dehydration, which is usually recognized through identifiable risk factors, clinical signs, and laboratory abnormalities, chronic dehydration develops insidiously and frequently goes unrecognized. This is particularly true in older adults, among whom many of its nonspecific manifestations, such as weakness, constipation, headache, dizziness, gait instability, and confusion, are often mistakenly attributed to normal aging. This population is especially vulnerable to chronic dehydration because of age-related normal physiological changes, compounded by physical, cognitive, psychological, climate, and other environmental influences. Inadequate hydration is associated with impairments in physical, cognitive, and emotional functioning, reduced alertness, and diminished exercise tolerance. It may also alter drug pharmacokinetics and pharmacodynamics, increasing the risk of medication-related adverse events. Emerging evidence suggests that chronic dehydration contributes to neurocognitive decline and the progression of some chronic diseases, while increasing susceptibility to acute fluid deficits associated with substantial morbidity and mortality. Because its presentation is often subtle and nonspecific, recognizing chronic dehydration in older adults, including those who are otherwise healthy, requires a high index of suspicion. Greater awareness is essential for prevention, early detection, and management of chronic dehydration in this vulnerable population.