How to Prevent, Detect, & Treat
Dehydration in Aging Adults

By Leslie Kernisan, MD MPH

Questions about dehydration in the elderly are common. These may include: How to get them to drink more water, how is dehydration related to UTIs , Do coffee and tea count ?

Best approaches include:

  1. Frequently offering the older person a drink, preferably on a schedule,
  2. Offering beverages, the person seems to prefer, as juices, water, flavored or plain.
  3. Not expecting older adults to drink a large quantity at a single sitting,
  4. Addressing any continence issues that might be making the person reluctant to drink often.

Dehydration can be hard to correctly diagnose.

The Basics of Dehydration

Dehydration means the body doesn’t have as much fluid within the cells and blood vessels as it should.
Normally, the body constantly gains fluid through what we eat and drink, and loses fluid through urination, sweating, and other bodily functions. But if we keep losing more fluid than we take in, we can become dehydrated.

If a person starts to become dehydrated, the body is designed to signal thirst to the brain. The kidneys are also supposed to start concentrating the urine, so that less water is lost that way.

Older adults at higher risk for dehydration

The body’s mechanisms meant to protect us from dehydration work less well as we age. Older adults have reduced thirst signals and also become less able to concentrate their urine.

Other factors that put older adults at risk include:

Dehydration can also be brought on by an acute illness or other event. Vomiting, diarrhea, fever, and infection are all problems that can cause people to lose a lot of fluid and become dehydrated. And of course, hot weather always increases the risk of dehydration.

Finally, older adults are more likely to be taking medications that increase the risk of dehydration, such as diuretic medications, which are often prescribed to treat high blood pressure or heart failure.

If you’re concerned about dehydration in a frail elderly person have them drink some fluids and see if they perk up or improve noticeably. (This often happens within 5-10 minutes.)

If drinking some fluids does noticeably improve things, it suggests that the older person was mildly dehydrated.

The most accurate way to diagnose dehydration is through laboratory testing of the blood.

Physical signs of dehydration may include:

Dehydration especially in older adults, can cause weakness, dizziness and falls. In people with Alzheimer’s or other forms of dementia, even mild dehydration can cause noticeable worsening in confusion or thinking skills.

Dehydration also often causes the kidneys to work less well, and in severe cases may even cause acute kidney failure.

Chronic mild dehydration can make constipation worse. Also associated with it is kidney stones.

Mild dehydration can usually be treated by having the person take more fluids by mouth. Generally, it’s best to have the person drink something with some electrolytes, such as a commercial re-hydration solution, a sports drink, juice, or even bouillon. But in most cases, even drinking water or tea will help.

Mildly dehydrated older adults will often perk up noticeably after they drink some fluids, usually within 5-10 minutes.

Moderate dehydration is often treated with intravenous hydration in urgent care, the emergency room, or even the hospital.

Severe dehydration may require additional intervention to support the kidneys, and sometimes even requires short-term dialysis.

Prevent of dehydration

Older adults should consume corresponds to 57.5 fluid ounces, or 7.1 cups.

The best fluids include decaffeinated drinks. But if an older person particularly loves her morning cup of (caffeinated) coffee, consider accommodating her if at all possible.

How to help older adults to stay hydrated ■