Clinical Nutrition, August 2023 | Ellice Parkinson et al., University of East Anglia
About 1 in 4 adults over 65 are dehydrated on any given day—not because of illness, exposure, or weather, but because they simply aren’t drinking enough.
A systematic review and meta-analysis published in the journal Clinical Nutrition analyzed 61 studies covering more than 22,000 older adults and found that low-intake dehydration is far more common than most people realize. Among long-term care residents, the dehydration rate climbed to 34%. Among those managing multiple chronic conditions, it reached 37%.
The consequences extend well beyond thirst. Research links chronic underhydration in older adults to falls, frailty, infections, hospitalization, and premature mortality.
What drives those numbers is a physiological shift that happens gradually. As the body ages, the neurological sensors that detect rising sodium concentration in the blood—and trigger the urge to drink—become less sensitive. A separate Pennsylvania State University study found that 29% to 39% of middle-aged and older adults were dehydrated at any given time, even with full access to quality drinking water. They were not in difficult circumstances. They simply never felt thirsty enough to drink what their bodies needed.
Fatigue compounds the problem. It makes the early signs of thirst harder to notice, making the shortfall harder to correct—a feedback loop that worsens as the thirst signal grows less reliable.
For younger adults, simple checks like urine color and skin elasticity can offer a clue about hydration status. But in older adults, those signs are not always reliable. Research in older populations shows that skin turgor, urine color, dry mouth, and thirst sensation can all be misleading, and the usual signs of dehydration may be absent altogether. Hydration in older adults increasingly requires a deliberate habit rather than the trusty thirst signal of youth.
