Most of us have experienced dehydration at some point in our lives. In today’s article, we will discuss this topic in detail and understand how dehydration can affect our body. We will try to understand it through research conducted by several scientific institutions around the world. So, let’s begin today’s article.
Before we begin, we would like to mention that this article has been prepared entirely on the basis of scientific evidence and research.
How Does Dehydration Affect Your Body?
When your body starts running low on fluids, several normal functions can be affected. Water helps maintain normal blood circulation. It also helps regulate body temperature, support muscle function, aid digestion and help the kidneys remove waste from the body.
Because of this, dehydration does not usually affect only one part of the body. You may first notice that you feel more tired than usual. As you continue losing fluids, physical activity can become harder. Your body may also have more difficulty cooling itself. Changes in concentration, digestion, muscle function and urination may also appear.
These effects can become easier to notice when you put extra demands on your body. Exercising in hot weather or staying physically active for a long time can make the effects of fluid loss more obvious.
1. You May Feel Tired and Weak
Feeling tired or weak can be one of the early signs of dehydration. When your body loses fluids, blood volume and circulation can be affected. This can make it harder for your body to carry out its normal functions efficiently.
You may notice this even during everyday activities. A task that normally feels easy may suddenly feel more tiring. You may also feel that you have less energy than usual.
If you exercise while you are already dehydrated, this tiredness can become even more noticeable. Your body is already trying to maintain its normal functions. Exercise then adds another physical demand.
That is why dehydration can affect you even when you are resting. Once you start moving or exercising, the effects of fluid loss may become much easier to notice.
2. Your Physical Performance May Also Decline
As fatigue starts to appear, exercise can also become more difficult. During physical activity, your body produces heat. Sweating helps your body cool itself down.
The problem is that sweating also causes fluid loss. If you do not replace some of the fluids you lose, an activity that normally feels manageable may start feeling much harder.
You may get tired sooner. Your endurance may feel lower. You may also find it harder to maintain your usual pace or exercise intensity.
This is not only about exercise performance. Sweating is one of the main ways your body releases heat. So continued fluid loss can also make it harder for your body to regulate its temperature.
3. Your Body May Have More Difficulty Regulating Temperature
Your body temperature naturally rises when you exercise or spend time in a hot environment. Your body responds by producing sweat to prevent overheating. When sweat evaporates from your skin, it helps remove heat from your body.
However, if you are already low on fluids and continue sweating, your body may have less fluid available to support this cooling process. As dehydration becomes more severe, your ability to regulate body temperature can also be affected.
This is why staying hydrated during prolonged exercise or hot weather is about more than avoiding thirst. Having enough fluids helps support your body's natural cooling system.
There is also another important thing to remember about heavy sweating. You lose more than just water.
4. Fluid and Electrolyte Loss Can Affect Your Muscles
Sweat contains electrolytes such as sodium. When you exercise for a long time or sweat heavily, you can lose both fluids and electrolytes.
Depending on the situation, this can contribute to weakness, fatigue or muscle cramps. When your muscles are not working normally, your physical performance can also suffer.
This does not mean everyone needs an electrolyte drink every time they exercise. For normal daily activity, water and a balanced diet may be enough for many people. Electrolyte replacement becomes more relevant when fluid and electrolyte losses are significant. This can happen during prolonged or intense exercise or heavy sweating.
Your muscles are not the only part of your body that can respond to changes in hydration. Your brain can also be affected by a lack of fluids.
5. Your Brain and Concentration May Be Affected
Have you ever gone several hours without drinking and then felt sluggish or found it difficult to focus? For some people, dehydration can contribute to symptoms such as headache, fatigue, difficulty concentrating or changes in mood.
This does not mean every headache or concentration problem is caused by dehydration. These symptoms can have many different causes. But if they appear along with increased thirst, dry mouth, darker urine or other signs of fluid loss, dehydration may be one possible reason.
This is especially worth remembering if your day involves studying, working at a computer, driving or doing anything that requires sustained concentration.
The brain needs adequate fluids to function normally. The digestive system also depends on enough water.
6. Lack of Fluids Can Affect Digestion
Water supports normal digestion and helps keep stools softer. When you do not get enough fluids, your stools can become harder. This may contribute to constipation or make existing constipation worse.
At the same time, dehydration is not the only possible cause of constipation. Not getting enough fiber, being physically inactive, changes in routine and other factors can also play a role.
So drinking more water is only one part of supporting healthy digestion. A balanced diet with enough fiber, regular physical activity and adequate fluid intake all work together.
The kidneys are another part of the body that depends on proper fluid balance.
7. Severe or Prolonged Dehydration Can Affect the Kidneys
Your kidneys filter your blood. They also help regulate water and electrolyte balance and remove waste products through urine. Having enough fluid available supports these normal functions.
When dehydration becomes severe or continues for a long time, the body's fluid balance can become disrupted. In some cases, this can put extra stress on the kidneys and contribute to kidney-related complications.
This is why hydration is not something you need to think about only when you feel thirsty. Maintaining an appropriate fluid balance supports many important functions throughout the body.
If you have kidney disease or a healthcare professional has given you specific instructions about how much fluid you should drink, follow their advice instead of general hydration recommendations.
By now, it should be clear that dehydration is more than simply feeling thirsty. As fluid loss increases, it can affect your energy, exercise performance, temperature regulation, muscles, concentration, digestion and kidney function.
That makes it important to recognize the signs before the problem becomes more serious.
What Are the Common Symptoms of Dehydration?
Dehydration does not always happen suddenly. In many cases, fluid loss builds gradually. The first signs can be easy to ignore because they may feel like ordinary tiredness or the result of a busy day.
As the body's fluid deficit increases, these symptoms can become more noticeable. Recognizing the early signs gives you a better chance of addressing the problem before it becomes severe.
Symptoms of Mild to Moderate Dehydration
Common signs can include:
-
Increased thirst
-
Dry mouth
-
Darker urine than usual
-
Headache
-
Fatigue or weakness
-
Dizziness or lightheadedness
-
Lower energy
-
Difficulty concentrating
-
Reduced physical performance
Having one of these symptoms does not automatically mean you are dehydrated. However, when several symptoms appear together, it may be a good reason to pay closer attention to your fluid intake.
Thirst, dry mouth and darker urine occurring together can be useful clues. Still, no single symptom should be treated as a perfect test of hydration.
If fluid loss continues and is not replaced, dehydration can become more serious.
Signs of Severe Dehydration
Severe dehydration can cause symptoms that go beyond normal thirst or tiredness. These may include:
-
Confusion
-
Fainting
-
Severe weakness
-
Very little or no urination
-
Severe dizziness
-
Being unable to keep fluids down
-
Symptoms that continue to get worse
These signs should not simply be treated as mild dehydration at home. Severe dehydration can become a medical emergency. This is especially true when a person cannot replace lost fluids or continues to lose fluids quickly.
If serious symptoms are present or your condition is getting worse, seeking medical attention is important.
But what causes dehydration in the first place?
What Causes Dehydration?
Dehydration happens when your body loses more fluid than it takes in. Not drinking enough water is one obvious cause. But it is not the only one.
Exercise, hot weather, heavy sweating, vomiting, diarrhea, fever, illness and certain everyday habits can all increase your risk of becoming dehydrated.
Exercise and Excessive Sweating
When you exercise, your body produces more heat and responds by sweating. Water leaves your body along with that sweat.
The longer and harder you exercise, the more fluid you may lose. If you do not replace those fluids, dehydration can gradually develop.
The environment also matters. Exercising in hot or humid conditions can increase sweating. This can increase your fluid needs as well.
Hot or Humid Weather
Your body has to work harder to maintain a normal temperature when the weather is hot. One way it does this is by producing more sweat.
If you spend a long time outdoors, work in the heat or exercise in hot weather without taking in enough fluids, dehydration can develop more quickly.
That is why hydration becomes especially important during hot weather.
Vomiting and Diarrhea
Vomiting and diarrhea can cause the body to lose significant amounts of water and electrolytes. When these symptoms happen repeatedly, replacing those losses can become difficult.
The risk becomes even greater when a person cannot drink enough or cannot keep fluids down.
In these situations, replacing both fluids and electrolytes may be important. Medical advice may also be necessary if the symptoms are severe or continue for a long time.
Fever and Illness
Fever can increase fluid loss. Being sick can also reduce how much a person drinks.
For example, someone who is ill may not feel thirsty. They may have little appetite or may find it difficult to drink because of nausea or vomiting. This can create a situation where the body is losing more fluid while taking in less.
That combination can increase the risk of dehydration.
Alcohol Consumption
Alcohol can contribute to fluid loss. This can be more noticeable when you are not drinking enough non-alcoholic fluids alongside it.
This may contribute to symptoms such as thirst, dry mouth, headache and fatigue afterward. However, these symptoms can have several possible causes and should not automatically be blamed on dehydration alone.
Simply Forgetting to Drink
Sometimes there is no illness, intense workout or extreme heat involved. You simply get busy and forget to drink.
Work, travel, long hours outdoors or constantly putting off drinking water can all lead to lower fluid intake during the day.
Because dehydration can develop in such ordinary situations, making hydration part of your routine is often more practical than waiting until you feel extremely thirsty.
How Much Water Should You Drink?
There is no single amount of water that is ideal for everyone. Your fluid needs can vary depending on your physical activity, climate, sweating, diet, age and overall health.
For example, someone exercising for a long time in hot weather may need more fluids than someone spending a normal day indoors. Your fluid needs can also change during illness, fever, vomiting, diarrhea or periods of heavy sweating.
It is also important to remember that your total fluid intake does not come only from plain water. Other beverages and water-rich foods such as fruits and vegetables also contribute to the fluid your body receives.
Because everyone has different needs, it is better to think about hydration according to your individual situation rather than assuming that one fixed amount is right for everyone.
If you have a medical condition that affects your fluid or electrolyte needs, follow the advice given by your healthcare professional.
Sometimes even a person who normally drinks enough can become dehydrated because of unusually high fluid loss. When that happens, simply going back to your normal drinking habits may not be enough. You also need to focus on replacing what you have lost.
How Can You Recover From Dehydration?
Recovery mainly depends on how much fluid you have lost and why the dehydration happened.
For mild dehydration, gradually taking in enough fluids may help your body return to its normal fluid balance. If you have been sweating heavily, replacing those lost fluids is important. Depending on the situation, you may also need to consider electrolytes.
Vomiting and diarrhea can cause significant fluid loss. They can also cause electrolyte loss. In these situations, replacing only water may not always be enough. An appropriate oral rehydration solution may be useful when fluid and electrolyte losses are significant.
For mild dehydration, some practical steps include:
-
Drink fluids regularly instead of waiting until you are extremely thirsty.
-
Replace fluids lost during exercise or heavy sweating.
-
Include water-rich foods such as fruits and vegetables.
-
Consider electrolyte replacement when heavy or prolonged sweating makes it appropriate.
-
If illness is causing fluid loss, focus on both hydration and recovery.
-
Pay attention to the reason behind the dehydration instead of treating only the symptom.
If you are becoming increasingly weak or dizzy, cannot keep fluids down, are urinating very little or your symptoms continue to get worse, it is safer to seek medical attention. Severe dehydration should not be managed on your own.
If you exercise regularly, another question naturally comes up. Should you work out while you are still dehydrated?
Should You Exercise While Dehydrated?
If you are already experiencing noticeable symptoms of dehydration, intense exercise is generally not a good idea.
Exercise increases body temperature and causes additional fluid loss through sweating. If your body is already short on fluids, pushing yourself physically can make the situation worse.
You may also experience more fatigue, dizziness or weakness. Your exercise performance may also drop.
A better approach is to give your body time to replace the lost fluids and return to a normal state before you resume strenuous exercise.
If you experience severe dizziness, confusion, fainting or significant weakness, do not exercise and seek medical attention.
For people who work out regularly, hydration should not be something you think about only after training. Having enough fluids throughout the day is part of supporting normal exercise performance and recovery.
This also brings up an important question for people who use cold water therapy. Is it a good idea to take a cold plunge while dehydrated?
Should You Take a Cold Plunge While Dehydrated?
A cold plunge should not be used to treat dehydration. Cold water immersion does not replace the water or electrolytes your body has lost.
If you are already experiencing symptoms of dehydration, your first priority should be addressing your fluid needs. This becomes especially important if you feel dizzy, severely weak or have other concerning symptoms.
Once you are adequately hydrated and feeling well, cold water exposure may be considered as part of an exercise recovery routine. Whether it is appropriate for you depends on your individual needs and circumstances.
The important difference is that hydration and cold water therapy serve different purposes. Hydration provides something your body needs to function. Cold water therapy is a recovery practice that some people choose to include in their routine.
Being hydrated also does not automatically mean cold exposure is right for everyone. People with certain medical conditions or concerns should discuss cold-water exposure with an appropriate healthcare professional before using it.
Hydration and Exercise Recovery
Good recovery does not depend on one technique. After a workout, your body needs enough fluids, nutritious food, quality sleep and appropriate rest.
Cold water exposure, mobility work, stretching and other recovery practices can be included alongside these basics. They should not be treated as replacements for them.
If you want to make cold water therapy part of your routine, it makes sense to get the basics right first. Stay adequately hydrated. Eat a balanced diet. Get enough sleep and give your body enough time to recover.
Once these basics are in place, cold plunging can be added according to your goals and routine.
For people who want to use cold water therapy regularly at home, a dedicated cold plunge can make the practice more convenient. It can also make it easier to include cold water therapy consistently in your recovery and wellness routine.
Modouge offers cold plunge solutions designed for people who want to include cold water therapy in their home recovery and wellness routine.
Whether you use a cold plunge or not, hydration remains something your body needs every day.
How Can You Stay Properly Hydrated?
The simplest way to stay hydrated is to make drinking fluids a normal part of your daily routine. Keep water nearby and drink regularly throughout the day instead of waiting until you become extremely thirsty.
Your fluid needs may increase when you exercise, sweat heavily, spend a long time in hot weather or work in a physically demanding environment.
The same is true during illness. Fever, vomiting and diarrhea can increase fluid loss. That makes it even more important to pay attention to hydration during these situations.
Water-rich foods such as fruits and vegetables can also contribute to your overall fluid intake. If you exercise for long periods or sweat heavily, consider whether electrolyte replacement is appropriate for the amount of fluid and electrolyte loss you are experiencing.
The goal is not to constantly worry about hydration. It is simply to make adequate fluid intake part of your normal routine. This can help you avoid constantly trying to catch up after becoming dehydrated.
Still, there are situations where dehydration can become serious even when you are trying to stay hydrated.
Who Is More at Risk of Dehydration?
Dehydration can happen to anyone. However, some people may be more vulnerable to significant fluid loss.
These include:
-
Young children
-
Older adults
-
Athletes and people who exercise for long periods
-
People who work or spend extended periods in hot environments
-
People experiencing vomiting or diarrhea
-
People who are ill
-
People with certain medical conditions
-
People who have difficulty getting enough fluids
Older adults may not always feel thirst as strongly as younger adults. Young children can also lose a significant amount of fluid relatively quickly.
People who exercise heavily or work in hot environments may have higher fluid needs because they lose more fluid through sweating.
For these groups, paying attention to hydration can be particularly important.
When Should Dehydration Be Taken Seriously?
Mild dehydration may improve after adequate fluid intake. Significant fluid and electrolyte loss can become much more serious.
Do not ignore symptoms such as:
-
Confusion
-
Fainting
-
Severe weakness
-
Very little or no urination
-
Being unable to keep fluids down
-
Severe dizziness
-
Symptoms that continue to worsen
Severe dehydration can become an emergency. This is especially true when fluid loss is continuing or a person cannot replace what they have lost.
The risk can also be greater for young children, older adults, people who are ill and people with certain medical conditions.
So dehydration should not always be dismissed as simply “not drinking enough water today.” If your body continues to show warning signs or your symptoms are getting worse, getting medical help is the safer choice.
Finally lets take a look at the medical research conducted on this topic.
1. Scientists from the U.S. Army Research Institute of Environmental Medicine Explained Why Heat and Dehydration Put Additional Stress on the Body
In 2010, Samuel N. Cheuvront, Robert W. Kenefick, Scott J. Montain, and Michael N. Sawka published an important scientific review explaining the relationship between heat, exercise, and dehydration. These scientists were associated with the U.S. Army Research Institute of Environmental Medicine.
Their research was published under the title “Mechanisms of Aerobic Performance Impairment with Heat Stress and Dehydration.” It was published online on August 5, 2010, and was later published in the Journal of Applied Physiology.
This was not an experiment conducted on a single individual. Instead, the scientists reviewed previously available research in exercise and physiological science to understand what changes occur inside the body during heat exposure and dehydration.
Think of it through a simple example. When a person exercises in hot weather, their muscles continuously need blood and oxygen. At the same time, the body must release excess heat to keep its temperature within a normal range. If the body also becomes dehydrated during this process, maintaining this balance can become more difficult.
The researchers explained that heat and dehydration can place additional stress on the heart and circulatory system. The body has to balance the need to regulate its temperature with the need to deliver blood to active muscles. This situation can affect physical performance during prolonged or strenuous exercise.
The most important message from this research was that heat and dehydration occurring together can be more challenging for the body than either condition alone.
2. Eric D. B. Goulet’s Research Found That the Relationship Between Dehydration and Exercise Performance Is Not Always Straightforward
In 2011, Canadian researcher Eric D. B. Goulet analyzed several existing studies to understand the relationship between dehydration and exercise performance.
His research was titled “Effect of Exercise-Induced Dehydration on Time-Trial Exercise Performance.” It was published in the British Journal of Sports Medicine and was published online on March 31, 2011.
Rather than drawing a conclusion from a single small experiment, Goulet combined previously published studies and conducted a statistical analysis. The final analysis included 5 studies and a total of 39 participants. In these experiments, participants mainly performed time-based cycling exercises.
During exercise, participants experienced an average body-weight reduction of approximately 2.2%, indicating a loss of body water.
However, the result of this research was somewhat interesting. During self-paced cycling exercise, the researcher did not find a statistically significant decline in performance after approximately 2.2% dehydration.
This does not mean that dehydration is beneficial for the body. It simply means that the effect of dehydration on exercise performance is not the same under every circumstance.
The type of exercise, environmental temperature, exercise pace, body temperature, and the amount of water lost can all influence the outcome.
Therefore, a better way to understand this research is that a relationship between dehydration and physical performance may exist, but that relationship can vary depending on the circumstances.
3. Matthew T. Wittbrodt and Melinda Millard-Stafford at the Georgia Institute of Technology Studied How Dehydration May Affect Brain Function
Now let us look at a part that may be particularly interesting to most people—can dehydration also affect the brain?
To explore this question, Matthew T. Wittbrodt and Melinda Millard-Stafford conducted an important study in 2018. The study was published in Medicine & Science in Sports & Exercise in November 2018.
The researchers analyzed 33 previously published studies involving a total of 413 participants.
Across these studies, dehydration ranged from approximately 1% to 6% of body weight. The researchers examined how dehydration affected attention, reaction time, decision-making, physical coordination, and other cognitive functions.
The results showed that dehydration had a small but statistically significant negative effect on cognitive performance.
The effects were particularly observed in areas such as attention, executive mental function, and physical coordination.
The study also indicated that when water loss exceeded approximately 2% of body weight, its effects on certain cognitive functions could become more noticeable.
However, one important point needs to be understood. It would not be accurate to say that “dehydration causes permanent brain damage” based on this research. The study did not examine permanent brain damage. Instead, it mainly examined how dehydration can affect a person's ability to perform certain mental tasks while they are dehydrated.
5. Researchers from Charles Sturt University Found Different Results Regarding Dehydration and Mental Performance
In 2019, Stephen P. J. Goodman, Ashley T. Moreland, and Frank E. Marino published another important study on the same topic.
Their goal was to determine how much mental performance actually declines when a person experiences approximately 2% body-weight loss from dehydration.
They systematically analyzed previously available scientific studies and examined mental functions such as attention, decision-making, learning, and memory.
The results differed somewhat from the 2018 study.
The researchers did not find consistent and clear evidence that approximately 2% dehydration significantly impairs mental performance under every circumstance.
At first glance, this may appear contradictory. One study connects dehydration with reduced mental performance, while another does not find such a clear effect.
But this is not unusual in science.
The conditions of the studies were different. Some involved exercise, environmental conditions varied, the amount of dehydration could differ, and the tests used to measure cognitive performance were also different.
Therefore, when both studies are considered together, a more balanced picture emerges.
Dehydration may affect certain cognitive abilities, but the effect of moderate dehydration on mental performance is not necessarily the same or certain in every situation.
This is why, in a health article, it is more responsible to explain both sides of the research rather than simply claiming that “dehydration definitely reduces brain function.”
6. Dean Liszka and His Research Team Examined How Adequate Hydration Is Connected to Different Aspects of Health
In 2019, Dean Liszka, Eunice Mah, Tristin Brisbois, Pamela L. Barrios, Lindsay B. Baker, and Lawrence L. Spriet conducted a broad review of hydration and several aspects of health.
Their research was titled “Narrative Review of Hydration and Selected Health Outcomes in the General Population.” It was published in the journal Nutrients on January 1, 2019.
The research process was also systematic. The paper was submitted on October 17, 2018, revised on December 7, 2018, accepted on December 27, 2018, and published on January 1, 2019.
The researchers examined the relationship between adequate hydration and different aspects of health.
They reviewed scientific evidence related to mental performance, mood, headaches, kidney health, the digestive system, skin, and body weight.
The review particularly highlighted the importance of adequate fluid intake in relation to kidney stones.
When we consume enough fluids, urine volume can increase. This can help keep certain stone-forming substances more diluted in the urine, reducing their concentration. For this reason, adequate water intake is considered helpful in reducing the risk of kidney stones.
However, the researchers also pointed out an important limitation. The scientific evidence was not equally strong for every health outcome. Some findings showed an association but did not definitively prove that drinking more water was directly responsible for the health benefit.
7. Researchers Associated with the University of East London and King's College London Studied the Effects of Dehydration in Older Adults
As people age, the risk of dehydration can become more significant for some individuals. In 2021, Caroline J. Edmonds, Enrico Foglia, Paula Booth, Cynthia H. Y. Fu, and Mark Gardner published an important systematic review on this topic.
The study was titled:
“Dehydration in Older People: A Systematic Review of the Effects of Dehydration on Health Outcomes, Healthcare Costs and Cognitive Performance.”
It was published online on February 17, 2021, and was later published in Archives of Gerontology and Geriatrics.
The researchers searched for scientific studies available up to March 2018. They initially identified 1,684 research papers. After screening them, 18 studies were included in the final review.
These studies contained data from a total of 33,707 older participants. The participants were generally aged 60 or older and came from different settings, including communities, hospitals, and long-term care facilities.
The researchers found that dehydration in older adults was associated with several poor health outcomes. Some studies linked dehydration with higher mortality, longer hospital stays, and poorer health outcomes.
Some research also indicated possible associations between dehydration and frailty, recovery after surgery, and cognitive performance.
However, an important point should be kept in mind when interpreting this research.
The methods used across the studies were not identical. The methods used to measure dehydration also varied. Therefore, it would not be accurate to say that “dehydration is the cause of all these problems.”
The main finding is that dehydration in older adults appears to be significantly associated with several adverse health outcomes.
What Should We Ultimately Understand From All These Scientific Studies?
When these different studies published between 2010 and 2021 are considered together, one point becomes fairly clear: maintaining adequate hydration is important for overall health, but the effects of dehydration are not identical for every person or in every situation.
During heat exposure and exercise, dehydration can place additional stress on the body's ability to regulate temperature and maintain blood circulation. Under certain conditions, this can affect physical performance.
When it comes to the brain, the scientific evidence is somewhat more complex. Some studies associate dehydration with reduced attention and other cognitive functions, while other research does not consistently find such an effect with moderate dehydration.
Regarding kidney health, adequate fluid intake is particularly important, and sufficient water consumption may help reduce the risk of kidney stones.
Among older adults, available research associates dehydration with several adverse health outcomes, although not every association should be interpreted as a direct cause-and-effect relationship.
Therefore, the most scientifically balanced conclusion about dehydration is:
Dehydration is more than simply feeling thirsty. Its severity and effects can vary depending on a person's age, physical activity, environment, and health status. Scientific research has identified effects on physical performance, temperature regulation, kidney function, and certain cognitive processes, although the strength of the available evidence is not the same for every effect.
0 comments