How Dehydration Affects Your Body

We all want what’s best for our bodies — we schedule annual checkups, take medicine when we have illnesses, and do our best to prevent and manage diseases. Though all conditions that impact our well-being deserve our attention, there is one important issue that most people experience yet may not realize — dehydration. Dehydration occurs when the body does not take in enough water to replenish what is lost during normal bodily functions. Although it is natural for the body to lose fluids throughout the day, failure to replace them over time can lead to several other health problems.

Replenishing fluid levels is a healthy solution, but unfortunately, sometimes adults and children choose to consume alternate beverages that either do not provide the water volume needed or may even dehydrate the body further. Dehydration is a serious health concern and an impairment that can quickly impact men and women of all ages, so we should all take care to avoid it.

How Does Dehydration Affect the Body?

Knowing how dehydration affects the body means understanding why the absence of proper hydration can result in mild to severe health issues. As much as 60 percent of a fully grown  body is composed of water. Many individual organs and muscles are composed of higher percentages of water including the heart, lungs, skin, muscles, and kidneys. Water keeps the whole body functioning, doing everything from growing cells and delivering oxygen to regulating temperature and flushing out waste. Without water, the body cannot carry out these tasks.

What Causes Dehydration?

Dehydration occurs when the body does not have sufficient clean water. In many instances, dehydration happens simply because an individual isn’t drinking enough water. However, other causes of dehydration may include the inability to access clean drinking water, excessive sweating or urination that increases water loss, or the presence of a high fever, vomiting, or diarrhea due to an illness.

Who Is at Risk of Dehydration?

Although all people can suffer from dehydration, certain factors can increase the onset of this deficiency. Infants, children, and older adults may be more vulnerable to dehydration. Those with a disability are also at an increased risk, as well as those who experience increases in body temperature due to exercising or working outside.

The most notable signs and symptoms of dehydration in these at-risk groups include the following:

• Babies and infants: Young children have a low body weight, which means their bodies are acutely sensitive to even small amounts of fluid loss. Babies who are not producing tears as they cry should be given fluids as soon as possible.


• Older adults: It can be easy for older people to forget to monitor their daily fluid intake, making them less aware of when they are becoming dehydrated and in need of more fluids. Older adults may begin to feel disoriented or fatigued when they need to drink more fluids.


• People with a disability: Many people who are physically disabled have to rely on a caretaker to provide water. In some cases, the need for greater hydration may go unnoticed for more time than it would for an able-bodied adult who could get a glass of water on their own. If a person with a disability starts urinating less frequently, their caretaker should consider increasing their water intake.


• Athletes: For professional and amateur athletes, staying hydrated is key, especially during the hot and humid months. It is crucial for athletes to replace the fluids they sweat out while exercising. An athlete should always drink plenty of water, especially if they start feeling lightheaded or dizzy.

What Are the Symptoms of Dehydration?

The symptoms of dehydration are diverse and may differ between children and adults. Although a dry mouth and tongue are symptoms, an increased thirst for water isn’t necessarily the earliest indicator that you are dehydrated. Adults may notice less-frequent or dark-colored urination, dizziness, confusion, or fatigue. Children may be irritable or lack tears when they cry. Young ones may also have sunken areas on their face and head, or have no urination over a few hours.

What Complications Can Dehydration Lead To?

Because it could lead to serious health complications, dehydration should never be ignored. Heat injuries such as heat cramps, heat exhaustion, and heatstroke could occur without proper hydration. You could experience long-term kidney and urinary problems, seizures, and hypovolemic shock if your blood pressure drops too low. Some complications of dehydration can be life-threatening. Dehydration can also impact specific areas of the body in negative ways. The skin, muscles, kidneys, brain, and heart can all suffer from the effects of dehydration.

The Effects of Dehydration on Skin

Knowing that dehydration results from a lack of water and that it also can impact the skin, it’s easy to assume that dry skin is a symptom of dehydration.  Dry skin is common and can happen to men and women of all ages for a variety of reasons. Although the confusion is understandable, dry skin does not always indicate dehydration. Dry skin, known as xerosis, and in severe cases dermatitis, is caused by a variety of underlying factors. Dehydration does affect the skin, but it’s important to note the differences between dry skin and dehydrated skin.

Dry skin occurs from a lack of oil, while dehydrated skin occurs from a lack of water. Your skin can still feel oily yet dry and dehydrated at the same time. As the body’s hydration level drops, the skin cells are depleted of their water content, making the skin appear and feel rough. Even if you are drinking moderate amounts of water, you could still see signs of skin dehydration due to illness or dietary factors such as drinking too much caffeine, alcohol, or other diuretics.

Dry skin can either be a lifelong or temporary condition, and symptoms can vary depending on age, health, and other environmental factors. The most  common dry skin symptoms include:

• Itching


• Redness


• Skin cracks


• Flaking


• Scaling


• Peeling


• Tight/rough texture

Along with full-body dehydration symptoms like dry mouth and dizziness,  symptoms of dehydration visible on the skin include:

• Sunken eyes


• Skin dullness


• Dark under-eye circles


• Increased wrinkling

The solution for dehydrated skin is proper full-body hydration. Washing your face or hands may feel refreshing, but it will not replenish your body’s hydration level. Keep in mind that taking hot showers or bathing in hard water can actually leave your skin more dehydrated. To help combat dehydration, you should also pay attention to environmental factors in your everyday life. Direct sunlight on the skin or activity during high temperatures can cause your body to dehydrate faster if you are not replenishing your fluids fast enough.

You can perform an at-home test to quickly help determine if your skin is dehydrated. Simply take a small portion of skin between your fingers and gently squeeze it. The skin should quickly bounce back to normal. If it does not, or if it begins to wrinkle as it returns to normal, your skin may be dehydrated. Unlike dry skin, dehydrated skin cannot be treated with topical creams. When you maintain proper hydration levels in your body, your skin will stay hydrated as well.

The Effects of Dehydration on Muscles

Dehydration  can cause physical fatigue. While many athletes or active individuals may feel soreness or stiffness in the muscles they exercise, many people may feel more than simply tired even if they aren’t engaging in activity. Slowed blood circulation due to dehydration can make muscles contract, which causes discomfort. The state of physical exhaustion and the presence of muscle spasms or cramps may be a direct result of dehydration that can occur even when someone has been seated or standing for a long time.



Sudden sharp pains or lumps on a muscle may be a muscle cramp. Muscle cramps may  occur for a variety of reasons, including overuse, strain, or dehydration. Most muscle cramping usually relaxes after a few minutes, is harmless, and doesn’t require treatment for dehydration. In cases of dehydration, the cramping should subside and water replenishment should reduce the likelihood of experiencing them. Severe pain or weakness, or cramping that is frequent despite an obvious cause, is likely not a result of dehydration. These cases may require medical care.

As a result of lower energy levels, one study suggests that dehydration also could  contribute to stalled muscle growth via muscle fatigue. The study observed weight-trainers as they worked out while dehydrated. This decreased their ability to perform their workout as optimally as possible, causing them to lose potential increases in muscle. Another study produced similar results, stating that the blood flow to the active muscles is reduced due to dehydration, especially during prolonged activity.

There is also a chance that those who exercise or perform strenuous physical activities while dehydrated may experience symptoms of delayed-onset muscle soreness. Also referred to as  delayed-onset muscle soreness (DOMS) occurs due to reduced cellular water levels. Symptoms include pain, stiffness, and swelling, and can be present within 24 hours to 48 hours after exercise and persist for up to four days. This type of muscle damage is usually mild and will not be permanent if the muscles are stretched, cared for, and kept hydrated.

Although dehydration alone does not cause DOMS, it is still a worrisome condition for those who are physically active on a regular basis, and thus, increases their rate of potential dehydration. The combination of dehydration and DOMS could lead to skeletal muscle damage that increases the risk of additional injuries. Factors like age, physical ability, and climate can increase the likelihood and severity of either condition which potentially elevates the risk of sustaining other muscular or skeletal injuries.

The Effects of Dehydration on Kidneys

The systems within our bodies work together to keep us healthy. The urinary system achieves that goal by eliminating waste, controlling our electrolyte levels, and regulating our blood’s volume, pH, and pressure. Made up primarily of the kidneys, ureters, and bladder,  the urinary system works with the lungs, intestines, and skin to maintain our body’s water level. The kidneys specifically filter waste from blood to create urine that gets expelled from the body. Without proper hydration, these organs become strained and can potentially incur severe damage.



Water plays a  critical role in the urinary system. As your body separates nutrients from waste, water opens up your blood vessels to allow blood to travel freely to your kidneys. After the blood and waste are separated, water mixes with the waste to become urine. Without enough water, the urinary system suffers and these organs have a difficult time accomplishing their tasks. Not only do they function less than optimally, but a lack of hydration can cause these harmful wastes to build up in the body.

While occasional dehydration is a condition many adults will experience throughout their lifetime, frequent dehydration can significantly impact the kidneys. Severe dehydration doesn’t need to be present to cause damage — even mild to moderate dehydration on a consistent or continuous basis is enough to cause damage to the kidneys that can be temporarily painful or permanently debilitating.  Kidney stones and urinary tract infections can result from dehydration, as well as other health conditions due to the buildup of waste and acid that’s not removed from the body.

In the most severe cases, these smaller issues resulting from dehydration could lead to permanent kidney damage or  chronic kidney disease. The onset of CKD may result from high blood pressure or diabetes. However, hydration still plays a part in its severity. Without water to help the kidneys function properly, it opens up opportunities for other health complications to increase due to the high amounts of waste buildup in the bloodstream. While hydration won’t necessarily prevent CKD, actively preventing dehydration can help preserve the health of your kidneys.



While increased water intake is a solution for dehydration in most individuals, it’s important to understand that appropriate water levels may vary for some men and women. While age and environment are always a factor, significant changes to the body such as pregnancy, childbirth, and chronic illness may require more or less hydration. Those with severe kidney problems may actually need to limit their water intake to keep these organs functioning correctly.

The color of your urine is a daily sign of your hydration levels that also sheds light on the state of your kidneys. Clear or lightly colored urine indicates that your body is well-hydrated. A darker coloration may indicate that you are dehydrated. A consistent or sudden change in urine color, or urine that is very dark, may indicate a more severe level of dehydration or another serious health issue. If your urine color lightens after drinking water, you are maintaining proper hydration. If it doesn’t, you should consult a doctor.

The Effects of Dehydration on the Brain

The brain is composed of  73 percent water — which means that even a few hours without water intake can substantially impact nearly every cognitive function. As little as 1 percent dehydration, which can occur within four to eight hours, is enough to negatively impact everything from mood and memory to cognitive performance and motor coordination. Without increasing water intake within this time, you may notice dehydration symptoms impairing your brain functioning, apparent by changes in:

• Mood


• Energy


• Focus/Memory


• Performance


• Brain Shape

Changes in mood or energy levels may be two of the first signs your brain uses to alert you of dehydration. Regardless if you are feeling healthy and rested or having a positive day that is stress-free, a disruption in the balance of sodium and water in your brain can quickly lead to disturbances in mood or feelings of fatigue. As your brain continues to operate without a proper water supply, cognitive functioning begins to decrease.

Although our brain does tell us that we are dehydrated, this indicator is slightly behind in real-time hydration levels — by the time our body lets us know we’re dehydrated, our organs have already experienced some impairment. This means that our  ability to concentrate, store, process, and recall information is inhibited before we realize it. Naturally, this is a problem — and it becomes a much larger issue due to the performance impairment we then experience.

Disruptions to your mood, energy levels, and ability to focus on and retain information all tie into poor cognitive performance and reduced motor skills. Studies have shown that even rote or basic actions are more difficult to complete when dehydrated. Our motor  coordination and reaction time suffers, especially during activities that are repetitive or not stimulating enough to fully engage us. One study even suggests that our cognitive performance while dehydrated is similar to our performance while under the influence of a small amount of alcohol.

Most of these cognitive impairments are caused by the physical changes the brain experiences during dehydration. The shape of the brain changes in two ways. First, ventricles in the center of the brain  expand rather than contract, causing the brain to swell. Studies have also found that brain tissue can shrink during dehydration. Neural firing patterns also change during this time. Neuronal activity significantly increases to compensate for the lack of water, making the neurons work harder to achieve normal performance results. 

Again, it’s important to understand that over-hydration is  also bad for your body. When you drink too much water, the kidneys cannot process the high volume. Excess water is stored in other cells, which causes the water-to-sodium concentration to become unbalanced and the cells to swell. The swelling of cells in the brain can lead to symptoms such as confusion. Too much cell swelling could potentially damage the brain to a permanent or fatal extent.

The Effects of Dehydration on the Heart

Like the brain, the heart is also largely composed of water. Together with the circulatory system, your heart is a primary part of your body’s  cardiovascular system — which also includes your blood and blood vessels. These parts work with the lungs, veins, arteries, and other vessels to carry blood throughout the body. The cardiovascular system relies on water in a similar fashion to the other systems throughout your body — without proper hydration, this system is strained and performance decreases.

The first two elements of the cardiovascular system that dehydration impacts are your  heart rate and blood pressure. When the body is dehydrated, blood vessels cannot stretch enough due to the reduction in blood volume. Your heart rate increases to compensate and attempts to pump more blood. The higher sodium content in a dehydrated bloodstream forces capillaries to close and blood pressure to increase. Thicker blood that is more concentrated is harder to move through the body so the vessels work harder to push the blood along.

One concern of lower blood volume due to dehydration is the  risk of orthostatic hypotension. You may have experienced this before from standing up too quickly and may have felt dizzy or lightheaded. This is a common occasional experience for many men and women, and the mild symptoms that occur usually dissipate quickly. However, severe or prolonged dehydration can cause orthostatic hypotension symptoms like weakness, nausea, or even fainting, which could then result in other accidental injuries.

For your body’s systems to operate properly, a consistent amount of blood needs to move throughout the body. The heart pumps a certain volume of blood out during each beat — this number is known as cardiac output. Although your blood pressure and heart rate have increased due to dehydration, your cardiac output is actually decreased. This puts a significant strain on your cardiovascular system as it works harder to pump less blood to the rest of your body.



Some studies have shown that dehydration can be a factor in the  onset of cardiovascular disease. It states that being unknowingly dehydrated can have the same negative impact on the blood vessels and arteries that smoking a cigarette does. Although severe cardiovascular strain is not healthy for any individual to experience, it is especially concerning because it could lead to other health problems in those with underlying diseases. People who are dehydrated due to activity and experience cardiovascular strain could potentially experience a sudden cardiac event if undiagnosed.

Tips for Staying Hydrated

Keeping hydrated doesn’t need to be difficult. Whether your schedule is constantly packed or if you rarely stray far from home, you can easily and effectively provide your body with the correct amount of water it needs by following these five tips:

1. Make water part of your daily routine. Performing any act, like drinking water, every day for just over two months will help you build a habit. Prioritize your water intake at key times of the day that you can typically control, such as drinking a glass when you wake up and as you wind down after dinner. Go out of your way to ingest the water you need, and before you know it, it will be a natural part of your everyday life.
2. Ingest water through alternative substances. A certain percentage of your daily water intake should come from food. Eating fruits and vegetables that are rich in water can increase your hydration levels. Be sure to wash any fresh produce before eating it or cooking with it. Using a home drinking water system from Multipure provides an endless supply of clean cooking and drinking water conveniently at your tap. You can also choose to drink flavored water beverages instead of plain water. Remember that liquids like coffee, soda, milk, and alcohol are not water alternatives.



3. Keep track of your water intake. Today’s technology puts valuable health tools in the palms of our hands. Some reusable water bottles have Bluetooth connectivity that reminds you when you’re not drinking enough. If nothing else, you can always purchase a reusable container that holds as much water as you need daily so you can track your progress from sunup to sundown.
4. Monitor your body for signs of dehydration. Your body will let you know when it’s dehydrated — listen to it. Pay attention to your urine color, keeping an eye out for dark coloring. If you find yourself becoming confused, irritable, or fatigued easily, you may need water.
5. Don’t over-hydrate. Too much water intake can actually dilute the body and cause other conditions that negatively affect your health. Learn to manage your intake so you can consistently keep your body at the correct hydration levels.

Don't Let Dehydration Damage Your Body

Dehydration is a concern for everyone, which is why staying hydrated should be a daily priority. Although it is understandable that you don’t always have the accessibility or availability to drink water, you can take proactive steps to ensure your hydration throughout the day. Multipure  home drinking water systems filter out a wide range of contaminants that can harm your body and provide your family with clean, healthy water that tastes good.

Browse our selection of  essential water filter systems for the home and discover how Multipure’s superior products deliver easy access to the refreshing water you need to keep your body hydrated throughout the day.

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