Dehydration in the Elderly
Home Blog Dehydration in the Elderly – All Questions Answered

Dehydration in the Elderly – All Questions Answered

by Dr. Nikola Djordjevic, MD

We all know that drinking lots of water is good for us. And most of us try to stay hydrated by following recommendations for how much liquids we should drink daily. But did you know that children and the elderly share a similar risk of becoming dehydrated? So are we doing enough to prevent dehydration in those who are most vulnerable? Dehydration in the elderly is a serious issue. It’s quite common, and it can have dangerous consequences. Yet, elderly dehydration is often overlooked.

In this post, we will explain every aspect of dehydration in general, with a special focus on dehydration in seniors, which we will cover in detail. What is dehydration? What are the symptoms of dehydration? Why do the elderly have a greater risk of becoming dehydrated? Keep reading, and you’ll get the answers to all of these questions, plus how to diagnose and treat dehydration in older adults—or better yet, prevent it from ever occurring. Let’s begin.

What Is Dehydration?

Dehydration is a term used to describe the lack of water in the body. When the body lacks water, it can’t function properly. Why do we become dehydrated? Quite simply, dehydration occurs when you lose more water than you consume. While everyone can become dehydrated, children and the elderly are especially susceptible, and it is most dangerous for them. Moreover, some dehydration symptoms in elderly people can be masked (for instance, skin tenting), which can lead to a delayed diagnosis.

Why is it dangerous? Water is essential for survival. Its lack can disrupt virtually every physiological process in the body. Can dehydration cause death in the elderly? Of course, extreme thirst can lead to death in a matter of days. Often, dehydration is diagnosed in the hospital when it has already caused a serious problem. That’s why it is important to know its causes and symptoms so that we can act swiftly to prevent and treat it.

What Causes Dehydration?

The following reasons can cause dehydration in any age group:

  • Not drinking enough water: The simplest and most common reason that leads to dehydration is merely not drinking enough water. Whether that may be a matter of habit or the lack of access to clean drinking water, you will become dehydrated if you neglect hydration. Note that dehydration in seniors can even result from neglect in nursing homes.
  • Vomiting and diarrhea: Another important reason can be an acute illness that causes diarrhea and/or vomiting. This can cause a massive loss of fluids and electrolytes (minerals), which often requires medical attention. Drinking water may not be enough to compensate for the loss.
  • Excessive sweating: Similarly to the previous point, excessive sweating due to vigorous activity, especially in hot and humid weather, leads to the loss of water and electrolytes. Why do the elderly get dehydrated quickly? Well, their reserve is smaller, and they use it up faster. Therefore, they should always stay hydrated in those situations if they want to prevent dehydration and heat exhaustion.
  • Fever: Another major cause of dehydration through the skin is fever. The higher the fever, the more liquid you lose by sweating. Fever is especially dangerous when combined with diarrhea and/or vomiting.
  • Increased urination: Finally, you can lose water through increased urination. This can be due to undiagnosed or untreated diabetes. Dehydration in older adults is also often caused by medications such as diuretics, which are usually prescribed for high blood pressure.

Dehydration in the Elderly

Why Is Dehydration More Common in the Elderly?

Numerous changes happen in our bodies as we age. That includes the very composition of our body and how it stores water. On top of that, chronic conditions and illnesses accumulate over time, as well as the medications we take to treat them, which can also contribute to dehydration. So the answer to the question “What causes dehydration in older adults?” is most likely to be found among the following reasons:

  • Body water composition changes: You probably know that two-thirds of our bodies are made up out of water. But this percentage actually varies substantially, and it is influenced by sex, age, and the percentage of body fat. Water constitutes over 70% of the body weight of a newborn baby, whereas less than 50% of the weight of some obese people comes from water. Older adults also have a low body water percentage, which is a major risk factor for dehydration.
  • Reduced sense of thirst: The second mechanism that plays an important role in the pathophysiology of dehydration in elderly people is the reduced sense of thirst. Older adults have a decreased sense of thirst which makes them less sensitive to dehydration. In other words, they can already be dehydrated before their alarm to drink water is triggered.
  • Kidney function decline: Also related to aging, the kidneys of many seniors become less efficient in conserving water while filtrating waste. As a result, they lose more water than necessary.
  • Mobility issues: A senior may have trouble moving for a number of reasons, which can include arthritis and other painful conditions. For this reason, they may become more and more reluctant to get up and go get water. This is a common cause of chronic dehydration in elderly people. Furthermore, if a senior is bedridden, they can be completely reliant on caregivers to bring them something to drink.
  • Incontinence: If an elderly person cannot control urination, they are more likely to abstain from drinking water and other liquids to avoid accidents. This can also easily lead to chronic dehydration.
  • Cognitive issues: Dehydration in elderly and dementia patients goes hand in hand. Alzheimer’s and other types of dementia and cognitive impairments can make an elderly person simply forget to drink water. Coupled with a weaker sense of thirst and other issues, dehydration is very likely to occur.
  • Medications: Last but certainly not least, many of the pills that seniors are taking can cause dehydration. This can happen as a direct result of their main mechanism of action, either as a side effect or as a result of interactions between different drugs. Diuretics (“water pills”), which are prescribed for high blood pressure, are the most common medications that cause dehydration when overused.

What Are the Symptoms of Dehydration in the Elderly?

The signs and symptoms vary depending on the severity of the condition. Not all of the early symptoms of dehydration in elderly people have to be present to arouse suspicion that a senior is on the verge of dehydration or already dehydrated.

It’s always a good idea to take a sip of water if you notice any of these early symptoms of dehydration in elderly people:

  • Dry mouth
  • Thirst
  • Dry skin
  • Less frequent urination
  • Dark urine
  • Constipation
  • Muscle cramps in limbs
  • Fatigue

If it is not addressed in its early stages, the following severe signs of dehydration in elderly people can quickly develop:

  • Lack of sweating and tears
  • Sunken eyes
  • Dizziness
  • Confusion and irritability
  • Low blood pressure
  • Weak and rapid pulse
  • Rapid breathing
  • Delirium and unconsciousness

Can dehydration cause confusion in the elderly? It certainly can. If a senior is suddenly showing signs of confusion or any other severe signs of dehydration in elderly people, they must see a doctor right away. For a senior, it always helps to have a medical alert system around, just in case.

What Are the Complications of Dehydration?

Why are we so concerned with dehydration? Because, if untreated, it can cause very serious complications, including the following:

  • Urinary tract problems: Frequent and long-standing dehydration is very likely to cause urinary tract infections, kidney stones, or even kidney failure—a life-threatening condition.
  • Heat injury: Vigorous exercise and heavy perspiration without proper hydration can lead to overheating and various degrees of heat injury. They can range from mild cramps to exhaustion or heatstroke, the most severe complication.
  • Seizures: Can dementia be caused by dehydration? Not really, but the confusion it causes can look like dementia. It can, however, cause full-blown seizures. How? Losing electrolytes, such as potassium and sodium, can cause a disruption in the electrical signals between cells. This, in turn, causes involuntary muscle contractions or a loss of consciousness.
  • Hypovolemic shock: Shock is a medical emergency that occurs when the body is not getting enough blood flow, meaning the cells and organs do not get enough oxygen and nutrients to sustain their function. It can occur due to the low blood volume caused by dehydration.

How Is Dehydration Diagnosed?

If you notice the above signs and symptoms and are concerned an elderly person might be dehydrated, there are a few ways to check it at home. Wondering how to test for dehydration in the elderly? If you have a blood pressure monitor, check to see if they have low blood pressure and a rapid pulse. Next, check for skin tenting by pinching their skin and seeing if and how quickly it returns to normal. This is an unreliable sign, and you shouldn’t delay a visit to the doctor’s office if the elderly person is unwell.

Your doctor will make an initial diagnosis based on the signs and symptoms of dehydration. However, the definite diagnosis has to be based on blood tests and urinalysis, which will reveal the full picture and the severity of dehydration. This will also determine the course of action and the treatment protocol. A blood test for dehydration in the elderly and the analysis of their urine can show us how concentrated the blood is, which can directly tell us if there is a lack of water in the body. We can also check if there’s an imbalance of electrolytes and how the kidneys are functioning.

How Do We Treat Dehydration in Elderly People?

The treatment of dehydration depends on the following factors:

  • The severity of dehydration,
  • The type of electrolyte imbalance, and
  • The cause of dehydration.
Dehydration in the Elderly

Mild dehydration is easily treatable, and the recovery from this type of dehydration in elderly people can occur after increasing oral fluid intake.

Water will do, but sports drinks which contain electrolytes can be a better solution.

Moderate dehydration needs to be treated in a hospital setting, such as the ER, because the loss of water and electrolytes have to be compensated through an IV.

Severe dehydration may even require dialysis in addition to all the treatments mentioned above.

If something specific, such as diarrhea or vomiting, is causing dehydration, we must also treat this underlying cause.

Preventing Dehydration in the Elderly

As you know, seniors have to take extra steps to ensure proper hydration. However, knowing the risk factors enables you to handle them one by one. Preventing dehydration is easy with the right plan.

Here are all the practical tips for preventing dehydration:

  1. Drink enough fluids: How much water should an elderly person drink a day? Experts recommend that older adults consume at least 1.7 liters (57.5 fluid ounces or 7.1 cups) of fluids per day. Notice that we said fluids, so it doesn’t have to be just water. Any liquid will do, but alcohol and coffee don’t count. In fact, they provide the opposite effect, because they act as diuretics. Make sure to drink extra fluids when it’s hot and when you are sick. Never wait to become thirsty—dehydration has already started at that point.
  2. Always have a variety of fluids around: What liquids are best for preventing dehydration in seniors? Water is best for preventing dehydration, but drinking only water can seem like a boring task. Having a variety of options, and having them close by at all times will definitely make it easier to increase your overall fluid intake. Choose natural juices and drinks containing a low amount of sugar or sports drinks that contain electrolytes.
  3. Eat foods with high water content: Water in foods counts too! Conveniently, foods that are high in water content are also very good for you and your diet. Eating fruits and vegetables, soups, yogurts, and so on will not only keep you hydrated but help you lose weight. Since we’re talking about dehydration prevention, elderly people are also prone to constipation. You can solve both problems at the same time by increasing fluid intake.
  4. Measure fluid intake: If you are concerned whether or not you or the person you are taking care of is drinking enough liquids, it helps to actually measure the fluid intake. You can even keep a journal—this can be especially useful for seniors who are unable to speak or move.
  5. Tackle underlying conditions and risk factors: Talk to seniors about anything that may prevent them from drinking enough liquids, such as mobility issues and incontinence. Educate them about the signs and symptoms of dehydration in the elderly as well as the dangers of dehydration, and solve these problems.

Dehydration in the ElderlyDehydration in the Elderly

Dehydration in the Elderly

Dehydration in the Elderly

Dehydration in the Elderly


We believe that elderly dehydration is a condition that’s been overlooked for far too long. Not only are seniors more prone to dehydration, but they are also more at risk of suffering serious consequences. This is in part because some symptoms can be masked. For instance, confusion can be contributed to old age, and some signs won’t be as evident on an older adult’s skin. So dehydration in the elderly can be discovered at a later stage and require a more complicated treatment. If you’ve read our guide, you’ve learned more than enough to prevent dehydration from ever occurring. If you have any additional questions, don’t hesitate to ask in the comment section below.

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