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How to stay hydrated as an older adult

From the desk of Robb Wolf

Many of us have aging parents, grandparents, friends, and loved ones — and many of us will be lucky enough to see our later years too. Getting older often comes with health challenges, and today we’ll discuss hydration through that lens.

As we get older, our total body water decreases, our thirst mechanisms may mislead us, and medical conditions can increase urinary water losses. It’s easier for dehydration to set in, and with it, a higher risk of heart issues, cognitive impairment, and fractures from falls.

But preventing dehydration as an older adult is just half the hydration story. Getting enough sodium is the other half, but older adults (and whippersnappers) often neglect it.

Many folks don’t understand: You can’t stay properly hydrated — you can’t feel and function as well as possible — if you guzzle plain fluids while shirking salt. That’s why sipping electrolyte water throughout the day is the main hydration strategy we’ll talk about today.  

Let’s talk about how to help ourselves and our older loved ones stay hydrated. Whether you care for an older adult or happen to be one, this article is for you.

Why Are Older Adults More Likely to Become Dehydrated?

Dehydration is rare in healthy people with access to water, but it affects 17–28% of older adults. Here are seven reasons why. 

#1: Less total body water

Younger adults are about 60% water by weight. By age 70, that figure drops to 40%, partly due to age-related muscle loss (muscle is one of the most watery tissues, around 76%). With less total body water, plus kidney decline making it “more difficult to concentrate urine and conserve body water,” older adults have a greater dehydration risk.

#2: Less thirst

Aging also often derails the thirst mechanism, our built-in dehydration preventer. 

Usually, thirst is an excellent guide to hydration needs (that’s why our advice for most folks is to drink to thirst to stay properly hydrated). However, age-related degeneration of brain receptors monitoring fluid balance means mild dehydration often goes undetected. No detection, no thirst. Less thirst leads to reduced fluid intake, making dehydration more likely.

#3: Less ADH

We also make less antidiuretic hormone (ADH) as we age. ADH helps the kidneys retain water, so less ADH means we excrete more fluids (think: urinary incontinence), hastening water losses. 

#4: Cognitive and physical impairments

Older adults with dementia may be unaware of their hydration needs, or unable to communicate them. Age-related immobility doesn’t help either. If it’s painful to walk, we’re less inclined to mosey to the fridge and grab a glass of water.

#5: Diagnostic confusion 

Many signs of dehydration mimic signs of natural aging. For example, dehydration can cause poor skin elasticity and sunken eyelids, but so can age-related declines in skin collagen. 

Dehydration can cause dry mouth, but so can pulmonary diseases and antihistamine use. 

You get the idea. This symptom overlap makes diagnosis a challenge. 

#6: Drugs and medical conditions

Getting old brings boundless wisdom and cheaper movie tickets, but also more health issues and medications to treat them. Here are some examples that increase dehydration risk: 

  • Medications that increase risk include diuretics, laxatives, ACE inhibitors, antihistamines, NSAIDs, chemotherapy, and others.
  • Medical conditions that increase risk include kidney disease, diabetes, cystic fibrosis, celiac disease, inflammatory bowel disease, and any illness that causes sweating, diarrhea, or vomiting. 

The next and final reason may be one of the most impactful. 

#7: Lack of hydration literacy

In a survey of 170 folks in retirement communities, researchers found that 60% overestimated the fluid loss needed to cause moderate to severe dehydration symptoms. In other words, they underestimated how easily one can become dangerously dehydrated. Similarly, 60% didn’t realize that fever (which causes sweating) is dehydrating.

They also underestimated the risks of overhydration. Just ⅔ of older adults in the survey understood that excess fluids could reduce blood sodium levels.

This comes back to misguided public messaging. Many older adults believe drinking eight glasses of plain water daily is a healthy habit — you’ve probably heard this, right? But eight glasses per day is actually a myth without scientific basis. Sodium has also been misrepresented as bad for your heart thanks to misguidance from confused health authorities

In the rest of this article, we’ll boost that hydration literacy. Let’s start with dehydration risks. 

Risks of Dehydration in Older Adults

The risks of dehydration depend on the magnitude of water deficit. For starters, mild dehydration (1% water loss from the body) can cause headaches, fatigue, dizziness, weakness, and muscle cramps. These risks apply to dehydration in any age group.

Even “mild” symptoms can have severe consequences, though, especially for older adults. For instance, dizziness and weakness increase the risk of falls and fractures, which are the seventh leading cause of death in adults over 65. Read longevity expert Dr. Peter Attia’s hydration article for a deeper dive. 

As body water continues to fall, symptoms can escalate to rapid heartbeat, dry mouth, poor urine output, and decreased skin elasticity. When dehydration becomes severe (5% water loss or more), decreased blood volume puts the heart under tremendous stress to get blood to the right places and oxygenate the organs. One consequence of reduced blood flow to the brain is cognitive and motor impairment. 

Researchers estimate that Medicare spends $5.5 billion annually on dehydration-related hospital admissions. Fixing this problem requires better hydration habits. Sodium is part of that fix. 

The Importance of Sodium for Older Adults

Water is only half the hydration puzzle. We’ll come back to that shortly. The other half of the hydration puzzle is sodium, and consuming enough of this crucial electrolyte is just as important for older adults as it is for younger folks and athletes. 

One of sodium’s primary jobs is regulating fluid balance. Proper sodium status keeps your blood flowing, brain functioning, and skin moist. Conversely, poor sodium status causes symptoms (often neurological) ranging from mild to severe.

Older adults are already more vulnerable to a sodium deficiency due to the lack of hydration literacy we discussed above. They’re also more vulnerable to sodium imbalances due to heart failure, kidney failure, and improper IV fluid administration. These risk factors can cause water to accumulate in the body without getting properly excreted, which dilutes blood sodium levels and can be even more dangerous than dehydration

To complicate matters, sodium deficiency symptoms — headache, fatigue, weakness, and cramps — are similar to dehydration symptoms. But if older adults address these symptoms by drinking more plain water, they’ll only feel worse. That’s why it’s crucial to include sodium in rehydration fluids. Let’s talk more about that.   

How Older Adults Can Stay Hydrated

We already mentioned the fundamental strategy for older adult hydration: Sip electrolyte water throughout the day. 

Before unpacking how to implement this strategy, let’s circle back to older adults’ hydration challenges. Implementation will follow naturally.

Older folks are more likely to become dehydrated because they have:

  • Less total body water, less thirst, and less antidiuretic hormone
  • Cognitive and physical impairments that impede fluid access
  • Other symptoms of aging that mimic dehydration
  • Fluid loss from drugs or medical conditions
  • Poor hydration literacy

The poor literacy applies to water and sodium, both of which support healthy hydration. By consuming fluids and electrolytes together, older adults can simultaneously prevent dehydration and low sodium symptoms.

Now for some tips for sipping electrolyte water throughout the day. Tactics can include:

  • Adding about 1 gram of sodium per 20–30 ounces of water to mimic healthy blood sodium levels (LMNT Drink Mix is a convenient and tasty option)
  • Keeping the drink close for easy access
  • Watching for dehydration symptoms to guide the volume and frequency of fluid intake (caretakers should be vigilant, too)
  • Working with a medical professional to determine an individual target daily fluid intake, since thirst may not be as reliable

Finally, older adults should understand why they’re sipping electrolyte water throughout the day. A little knowledge goes a long way toward habit formation. This article should help, though the best teacher is feeling the difference when you get it right.