Dehydration in Elderly: An Unseen Risk

Written by Cely Cen He & reviewed/edited by Katie Dodd, MS, RDN, CSG, LD, FAND

Cely is an undergraduate student at Queens College in New York majoring in Nutrition and Dietetics.


Dehydration in Elderly: An Unseen Risk

It’s a hot summer day and you are walking to the fridge to grab a cold refreshing drink. As you drink, you end up feeling refreshed, cooled down, and more alert. You probably didn’t think twice about getting a drink; it was just an instinct.

When we do not consume enough water or fluids, we become dehydrated. We don’t look or feel well, and that’s because our body relies on water to function properly. Dehydration is a condition that occurs when the body’s water supply is depleted without it being replenished.

It may seem like a small problem to younger adults, but it is a commonly overlooked problem among seniors that consequently creates other health concerns. The elderly frequently do not consume adequate fluids (8).

Keep reading to find out more on how to prevent and treat dehydration in the elderly.

Normal Hydration in Elderly

The human body is made up of approximately 60% water. Our major organs such as the brain, the heart,  and the skin, all contain a substantial amount of water (1). Your organs can’t function without having adequate water.

Water helps our body (2):

  • Maintain a normal temperature
  • Keep the joints lubricated and cushioned
  • Protect the spinal cord
  • Get rid of wastes (this occurs through urination, perspiration, and bowel movements)

Normal hydration is key to the overall well-being in elderly.

How much fluid do you need?

This is a commonly asked question, and the responses you have probably heard are:

  • to drink 8 glasses a day or
  • drink in ounces half your body’s weight.

However, there is no supporting scientific proof to support either of these recommendations.

How much fluid the elderly needs greatly depends on current body size, weight, medications, activity level, and the environment. Commonly used calculations for estimated fluid needs in the elderly include (8):

  • 1 mL fluid per calorie (based on caloric needs)
  • Urine output + 500mL/d (based on fluid balance)

The key to combating dehydration is to drink fluids frequently throughout the day.

What counts as water or fluid?

There are plenty of ways to stay hydrated, but not all liquids count. Even though water is the best source of fluid, some people just don’t like it. It can be perceived as boring and tasteless. Adding flavor to it or changing the texture can improve the experience of drinking water.

Common flavors to add to water include:

  • Sugar free sweeteners (ex. Crystal Light)
  • Fresh cut fruit (ex. limes, lemons, strawberries)
  • Fresh cut herbs (ex. basil, mint, etc.)

Other hydrating fluid options are:

  • Flavored water
  • Smoothies
  • Juices
  • Milk
  • Tea
  • Coffee
  • Sports Drinks

Instead of drinking water, why not eat water? Many fruits and vegetables are of high-water concentration such as watermelon, oranges, cucumbers, and lettuce. All of which are nutritious and hydrating. Check out this chart to find out more about water content of fruits and vegetables.

Coffee and tea may be associated with poor hydration status, but there is no supporting evidence that suggests it would necessarily lead to dehydration. In situations where someone just isn’t drinking enough water, drinking caffeinated drinks are OK (3).

hydrating foods


Dehydration in Elderly

The level of severity of dehydration varies by age groups. Dehydration risk increases with increasing age (8). Dehydration is a serious problem when it comes to the elderly. Let’s take a look at the causes and symptoms of dehydration, and why the elderly are at greater risk of dehydration.

Causes of Dehydration

Insufficient fluid intake is not the only cause of dehydration in the elderly. In fact, there are outside circumstances commonly found in the elderly that increase the likelihood of dehydration as well. Some, for example, are:

  1. Chronic Diseases or acute illness: may cause vomiting, diarrhea, and fever
  2. Prescribed Medications: increase water excretion, e.g. diuretics
  3. Sweating: water loss from exercise or hot weather

Symptoms of Dehydration

Dehydration may start out with mild symptoms but can quickly become severe in older adults. Thirst is a common symptom of dehydration, but it’s not a reliable indicator for older adults. You’ll find out why in the next section.

Some common symptoms to look out for are (4, 8):

  • Confusion
  • Psymptoms of dehydrationoor skin turgor
  • Dry mouth and/or tongue
  • Fatigue
  • Decreased pulse
  • Decreased blood pressure
  • Constipation
  • Concentrated urine (darker color)
  • Less output (not having to urinate as often)
  • Mood changes (ex. irritability or depression)

Why are Elderly at a Greater Risk?

The elderly are at greater risk of dehydration primarily because of physiological changes that take place as we age. Here’s a few examples:

Reduced Thirst Sensation

Most elderly have a lowered thirst sensation. By the time they feel thirsty, they most likely are severely dehydrated.

Loss of Muscle Mass

Muscle mass decreases at a rate greater than 3 – 8% per decade in seniors while accumulating more fat (5). The consequence of this is that their body retains less water. Muscle and contains water and if they have less muscle, there is less water.

Limited Mobility

Some elderly may have issues with mobility. Due to weakness or injury or medical conditions they may not be able to move well without the risk of falling (which can cause bone fractures and injuries). Immobility increases the risks of dehydration when water is not within reach. It can also lead to intentionally drinking less so they do not have to get up and use the restroom as frequently.

Loss of Taste and Smell

If these senses are impaired, the elderly may have decreased appetite and proneness to depression. They may also add excessive amounts of salt or sugar to their food and drinks in order to enhance taste.

Difficulty Swallowing

Difficulty swallowing, particularly undiagnosed issues can lead to a decrease in fluid intake. It is difficult to swallow so seniors just may avoid drinking. Also those on thickened liquids (for a diagnosed swallowing issue) may drink less due to not liking the texture.

Urinary incontinence

Fear of incontinence (accidentally wetting their bed or pants) can lead to someone avoiding or limiting intake of fluids. Some people may also limit or avoid fluids later in the day to avoid having to get up multiple times through the night to urinate.


Types of Dehydration

There are three types of dehydration, each categorized by fluid and salt concentrations in the body and by what caused the dehydration in the first place. It’s important to know the different types of dehydration in order for us to prevent or treat it effectively.

Water and Salt Loss “Isotonic Dehydration”

Isotonic Dehydration occurs when both water and sodium are lost. This can be caused by vomiting, diarrhea, sweating, and different medical conditions.

Salt Loss “Hypotonic Dehydration”

Hypotonic dehydration occurs when there is an excessive salt loss compared to water loss in the body. This is the least common type of dehydration. It is most commonly caused by long-term use of diuretics and following a low-sodium diet (8). It can also occur with very excessive and repeated vomiting or diarrhea.

Very rarely this type of dehydration can be caused by excessive intake of water with no or very little sodium. This has been known as a cause of death in water drinking competitions or challenges over the years.

Water Loss “Hypertonic Dehydration”

A form of dehydration that is more common in the elderly is hypertonic dehydration. It is categorized by a greater water loss in the body compared to salt loss caused by vomiting, fever, and of course, inadequate intake of fluids.

Treating Dehydration

Between 6% – 30% of seniors, aged 65 and above, who are admitted to the hospital are dehydrated. In 1.5% of these cases, dehydration is the primary cause for hospital admission (6).  The challenge in overcoming this issue is to increase fluid intake in the first place.

The best way to treat dehydration in elderly is to rehydrate gradually to supply the body with lost fluids and electrolytes.

Addressing the Root Issue

dehydration in elderlyTo treat and prevent dehydration, we need to know why it is happening. What is the root issue? Are they just not drinking enough fluid? If this is the case, then why? Do they not like water? Maybe they don’t have access to fluids? Do they have fear of incontinence? Problems swallowing?

Just telling someone to “drink more” is seldom the solution. You need to figure out why the dehydration is occurring.  This is an important step that cannot be missed.

Sometimes the root cause can simply be a lack of hydration knowledge. The elderly may not realize that their underlying illnesses and medications are putting them at a higher risk of dehydration. Many may also be not aware of the signs and symptoms as well.

Knowing the importance of hydrating can go a long way to improve the quality of life in older adults. Addressing the root issues of dehydration and finding ways to overcome these barriers can result in less hospital admissions and chronic problems.

Of note, older adults with dementia or other cognitive impairments may forget to drink water frequently. The responsibility for adequate hydration in these individuals falls on the caregivers.

Working with Healthcare Team

Many elderly patients are under the care of a family member, a caretaker, a hospital, or a nursing homes. It is important for professionals to educate the patient and their family to prevent and treat dehydration.

By raising awareness, people can assess and find ways to easily give water access to seniors to avoid dehydration, especially during times when there may be no one around to help.

Some methods can be leaving small water bottles that are within reach of the patient, providing moist food with high water content, and providing tasty fluids that the older adult wants to drink.  It is essential that health care worker monitor the elderly’s fluid intakes and provide support in increasing intake as needed.

Prevent Dehydration in Older Adults

Preventing dehydration in older adults is so important. It sounds easy, but it’s a challenging task to accomplish especially when some older adults may not feel the sense of thirst.

Instead of offering plain water to older adults, try other water or fluids that may be more enjoyable to eat or drink. Everyone has their own preference, so be sure to ask what their favorite fluids are.

Be sure fluids are provided with meals, snacks, and in-between meals. The more often fluids are offered, the more likely they are to be consumed.

Monitoring Intake & Symptoms

A simple way to make sure the elderly is well hydrated is by charting the frequency of water intake. It’s reliable and useful method to easily track their progress. This is particularly useful for elderly living in health care communities or who have a history of dehydration.

Another method is to check how often the elderly urinates, and what color the urine is.  The elderly should urinate every two to four hours, either colorless or pale yellow. If the urine is dark yellow, the elderly may be dehydrated. Note some medications can impact the color of urine.

Also be sure to monitor for the symptoms of dehydration discussed earlier in this article.

Tips to Increase Fluid Intakes

The most effective way to prevent dehydration is to drink more water or other fluids. However, some may find it difficult to drink enough. Below are a few tips to help you increase your fluid intake.

General Tips

  • Keep a journal to track fluid intake
  • Drink some fluids with every meal
  • Have a serving of water-rich fruits as snacks
  • Drink a glass of water after you wake up or before you go to bed
  • Drink a full glass of water every time pills are taken.
  • Keep a glass of water nearby at all times
  • Keep a beverage nearby when watching TV or reading or doing a puzzle
  • Try offering different temperatures of drinks

Flavoring Water

flavoring waterDrinking plain water can indeed be boring. You can spice it up by adding some citrus fruits like lemons or oranges, inside a water jug. Other fruits can likewise be a viable addition to your water: strawberries, raspberries, pineapple, cucumber, apple, and kiwi are some you can experiment with.

Here are some tasty flavored water combos to try (just add some cut up fruits and herbs to water and let the water soak up the flavors!):

  • Lemon water
  • Strawberry Basil water
  • Cucumber water
  • Blueberry mint water
  • Pineapple water
  • Raspberry lime water
  • Citrus (lemon, lime, orange) water



Dehydration, while detrimental to people of all ages, is more dangerous to the elderly. Not only are the elderly more prone to dehydration, it is also harder for us to detect the signs and symptoms of dehydration.

Drinking fluids frequently and addressing the root causes of dehydration significantly reduces chances of dehydration. This includes, plain or flavored water, smoothies, fruit juices, or water-rich foods.

If you’re unsure of your hydration needs, talk to your health care provider or a geriatric dietitian.

Dehydration in Elderly Infographic


  1. gov. 2020. The Water In You: Water And The Human Body. [online] Available at: <> [Accessed 30 June 2020].
  2. gov. 2020. Water & Nutrition | Drinking Water | Healthy Water | CDC. [online] Available at: <> [Accessed 30 June 2020].
  3. Maughan RJ, Griffin J. Caffeine ingestion and fluid balance: a review. J Hum Nutr Diet. 2003;16(6):411-420. doi:10.1046/j.1365-277x.2003.00477.x
  4. The Nutrition Source. 2020. Water. [online] Available at: <> [Accessed 30 June 2020].
  5. Elena Volpi, S., 2020. Muscle Tissue Changes With Aging. [online] PubMed Central (PMC). Available at: <> [Accessed 30 June 2020].
  6. 2020. [online] Available at: <> [Accessed 30 June 2020].
  7. Van der Sluijs E, Slot DE, Bakker EW, Van der Weijden GA. The effect of water on morning bad breath: a randomized clinical trial. Int J Dent Hyg. 2016;14(2):124-134. doi:10.1111/idh.12149
  8. Niedert K, Carlson M. Nutrition Care of the Older Adult. Chicago, IL: Academy of Nutrition and Dietetics; 2016.

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