Water is a critical element that is essential for human survival. The average human body is composed of over 60% water, distributed primarily through the lungs, muscles, skin, heart, and brain. Water plays an integral part in most of the functions of the body, acting as the primary building blocks for cells, regulating internal body temperature, metabolizing proteins and carbohydrates, and lubricating the joints.
The body requires an average of 3.2 liters every day to maintain healthy function. Drinking less than this amount can lead to dehydration, which has a number of negative effects on health. A recent survey of residents of the United States found that up to 75% of the population suffer from net fluid loss, which leads to chronic dehydration.
Inadequate water intake has been linked to a broad spectrum of diseases and disorders, including fatigue, poor cognitive function, metabolic syndrome, kidney disease, and even more concerning effects such as loss of consciousness, organ failure, and other life threatening conditions.
In this article, we’ll provide a list of the top ten indicators of dehydration as well as some techniques you can use to increase your water intake and improve your overall health.
Dehydration Dangers Explained
Dehydration occurs when the body uses more water than it absorbs, resulting in a variety of negative effects. The body uses water constantly to maintain tissue, flush toxins from the body, and digest food, but water is also lost through exhalation, urination, bowel movements, and sweat.
The primary cause of dehydration is inadequate water intake, but other factors such as excessively salty food or increased water consumption due to high levels of physical activity can also lead to dehydration. Following are some are the most common causes of dehydration:
- Inadequate water intake: Failing to provide your body with a sufficient amount of water results in net water loss, which can occur both quickly and slowly, and results in poor health.
- Environmental conditions: Hot weather or warm environments cause the body to lose water at a faster rate. Sweating induced by hot weather is a leading cause of dehydration. Statistics released by the EPA demonstrate that heat wave-induced mortality is responsible for more than 200 dehydration-related deaths annually.
- Intensive physical exercise: Intense physical exercise causes the body to sweat excessively in an attempt to regulate core body temperature. Water content in the body is lost through sweat, so it’s essential to drink extra water while exercising.
- Diarrhea, vomiting, and gastrointestinal diseases: Health conditions that induce vomiting or frequent bowel movements cause a net fluid loss that can lead to dehydration, as well as dangerously low electrolyte levels.
- Fever: Illnesses that induce fever in the body increase the core body temperature, which results in increased fluid loss through sweat.
- Skin burns or Infections: Skin infections and severe burns can lower the total water content of the skin, leading to dehydration. Sunburn can also induce severe dehydration, as can excessive sun exposure-induced heatstroke.
- Diabetes: Individuals that suffer from diabetes possess an inability to regulate their blood sugar level. To compensate, the body attempts to flush excess sugar from the system through frequent urination, which results in net water loss and dehydration.
Key Indicators of Dehydration: What to Look For
Dehydration is caused by a net fluid loss, which occurs when there is more water leaving the body than is consumed. Any factor that increases total water loss or consumption can lead to dehydration, which can manifest in a variety of symptoms.
Let’s take a look at some of the most common signs of dehydration:
Thirst is the first and most common indicator that your body requires more water. As an autonomous function of the body, thirst occurs due to a variety of physiological changes and chemical imbalances that occur when the water content of the body falls below a certain threshold. Thirst can also be influenced by a number of societal and psychological stimuli.
The biological machinery that causes a thirst response in the body are complex and extremely sensitive, able to detect minor changes in water volume. Hormonal changes in the body caused by low water levels are able to influence the chemical composition of the brain to induce the sensation of thirst. Older individuals are more prone to experiencing dehydration, as the cellular machinery responsible for these reactions becomes less sensitive over time, resulting in a less accurate perception of total water volume.
Drinking only when you’re thirsty, however, is not always the best way of preventing dehydration. If you’re participating in strenuous physical activity and are sweating profusely, it’s best to drink more water than is required by your thirst response to prevent dehydration before it happens. Ultimately, if you’re drinking water whenever your body tells you it’s thirsty, you should be safe from dehydration.
2. Changes in Urine Color or Volume
Urinary excretion is the primary way through which the body loses water volume. The urinary system includes the kidneys, which filter contaminants, waste, and toxins from the bloodstream and flush it, along with water, out of the urinary tract. When the water content of the body is low, the kidneys will conserve water by concentrating the waste volume of urine.
Urine volume and color have been scientifically proven to provide an accurate indication of the hydration level of the body. If the body is dehydrated, urine excretion will typically be lower in volume and appear as a yellow or darker color. The darker the color of your urine, the more severe the dehydration. In extreme cases of dehydration, the body will cease to produce urine altogether, which can lead to a dangerous buildup of toxins and other waste products that need to be expelled from the body.
There are a number of health conditions, foods, and environmental factors that can also influence the color and volume of urine produced by the body, but, as a general rule, it’s safe to assess your hydration levels by observing the volume and color of urine. A healthy body with an adequate water intake should expel urine that is almost clear in color, with no discernible odor.
3. Headaches or Migraines
Dehydration has been linked in multiple clinical trials and medical investigations to cause migraines. Commonly known as a water-deprivation headache, the physiological impact caused by inadequate water intake has been linked to oxidative and toxin-induced stress factors that are able to induce headaches and migraines.
A clinical trial performed in 2004 by the Loughborough University School of Sport and Exercise Sciences found that 37 hours of water deprivation leads to a total body mass decrease of 26% and induces acute headaches, as well as an inability to concentrate. Another 2004 clinical trial conducted by the UK National Hospital for Neurology and Neurosurgery demonstrated that the headaches induced by inadequate water intake can be effectively and completely cured within half an hour of drinking water.
There are many different forms of headaches and migraine pain, with as many different sources, but if you’re experiencing frequent headaches paired with any of the other symptoms on this list, it’s likely that you’re suffering from dehydration. Increasing your total water intake has a proven beneficial and preventative effect against headache frequency and severity.
4. Excessive Tiredness or Fatigue
Chronic fatigue, sleepiness and tiredness are complex conditions that can be caused by multiple factors including poor sleeping habits, insomnia, oxidative stress, anxiety, and cardiovascular disease, but the primary cause of these conditions is inadequate water intake. Similarly to headaches, many clinical medical studies have provided evidence of a strong link between dehydration and fatigue.
Low water intake has been demonstrated to affect the metabolism of the body and decrease the rate at which the digestive system is able to harvest energy from dietary intake, resulting in lowered blood flow and poor cardiovascular performance. A 2003 clinical trial performed by the US Army found that fluid loss resulting in an overall mass reduction of over 2% body weight results in significant adverse effects on exercise performance and energy levels.
A similar investigation into the effects of dehydration on physical performance in 2011 found that even smaller amounts of net fluid loss resulting in a mass decrease of less than 1% is still able to significantly impact physical performance, so it’s clear that maintaining adequate water intake is critical to avoid fatigue and tiredness.
If you’re feeling as though you’re constantly tired, or are finding physically-taxing tasks inordinately difficult, you may be suffering from dehydration. Drinking at least 15 cups of water spaced out throughout the day, especially when performing physical exercise, can help to avoid this unwanted symptom.
5. Skin Health Changes
The appearance of the skin is an extremely accurate indicator of the total health of the body. Changes in skin texture, cosmetic blemishes such as spots or wrinkles, and a loss of skin elasticity are all key signs that you may be suffering from dehydration. The skin is composed of over 30% water, meaning when the total water volume of the body decreases the skis is one of the first places to suffer.
The water volume of the skin is partly why it is so motile and flexible, so when reduced water intake causes dehydration, the skin usually appears dry, inflexible, and can often crack. Dehydration causes the body to draw water away from the extremities and the skin in favor of preserving critical internal organs.
The easiest way to test whether dehydration is affecting your skin is to pinch the skin of your upper arm between your thumb and forefinger. When the body is adequately hydrated, the skin should return to a smooth, firm state immediately. Dehydration will cause skin to take a short amount of time to return to a smooth state.
Ensuring you’re getting enough water will not only prevent dehydration from damaging your skin, but will also help to prevent the key signs of premature skin ageing such as wrinkles, fine lines, and crow's feet from occurring.
6. Cardiovascular Abnormality
Dehydration can also cause a number of concerning cardiovascular effects. A severe lack of hydration can cause the heart to function abnormally, either inducing heart palpitations and an irregular heartbeat, or tachycardia, a dangerously fast heart rate. These symptoms occur when the body attempts to make up for the lack of fluid content in the body.
The total volume of blood in the blood vessels is determined by the hydration level of the body. When the body is inadequately hydrated, the total amount of blood in the body decreases, which forces the heart to work harder in order to provide muscles and organs with fresh oxygen and nutrients. This can also present as an arrhythmia, or a strange, irregular heartbeat.
Cardiovascular irregularities are normally only caused by severe dehydration, but can also occur in less severe cases. If you’re experiencing any form of cardiovascular abnormality, it’s essential to seek professional medical advice immediately. Insufficient blood volume in the body can lead to the shutdown of critical organs as they are starved of oxygen, which can be fatal.
Always consult a medical professional if experiencing any concerning symptoms in your heart. Increased water intake, however, can significantly reduce the risk of developing cardiovascular disease, so if you have a family history of any form of cardiac disorder, always be sure to maintain adequate hydration.
7. Muscle Cramps
The fluid loss that is caused by exercise-induced sweating can result in rapid onset dehydration. Sweat contains both water content and high levels of sodium, which is integral in the chemical processes involved in muscle contraction and physical activity. When sodium levels reach critically low levels, the lack of mineral content in the bloodstream can lead to painful involuntary muscle contractions, known as cramps.
Cramps can be especially dangerous in activities like swimming, or significantly inhibit performance in competitive events. If you’re practicing any kind of strenuous physical activity or sport, always be sure to maintain adequate hydration to prevent muscle cramps. Sports drinks supplements that are low in sugar and rich in electrolytes can also provide a great deal of protection from dehydration-induced involuntary muscle cramps.
8. Low Blood Pressure
The decrease in total blood volume that ensues from insufficient hydration can also lead to a number of health conditions that affect factors apart from heart function. Low blood volume induced by dehydration has been proven to cause low blood pressure in multiple clinical trials, which can have a wide range of negative health effects.
Low blood pressure can cause dizziness, light-headedness, inability to concentrate, blurred vision, fatigue, respiratory complications, nausea, fainting, and other dangerous health conditions. Fainting, also known as syncope, is one of the more dangerous symptoms of this condition. Syncope is usually experienced when transitioning between seated or supine states and standing, as the body lacks the sufficient blood pressure to deliver blood to the brain.
Dehydration, in less severe forms, can cause a minor drop in blood pressure which is not grounds for significant worry, but can severely impact health in more advanced stages. If you’re experiencing any symptoms that lead you to believe you may have low blood pressure, it’s important to seek the advice of a medical professional. Small variations in blood pressure, however, can usually be alleviated by drinking extra water.
9. Poor Cognitive Function or Mood Swings
Water plays a critical role in the function of the brain. Dehydration has been observed in multiple trials to exert a negative effect on both cognitive ability and emotional balance. Insufficient water intake is able to imbalance the neurochemistry of the brain, which results in increased irritability, mood swings, and impaired executive function.
One of the mechanisms through which dehydration is able to induce increased irritability is through the sense of smell. A 2015 clinical trial observed a link between attenuated olfactory function and dehydration, causing participants to find unpleasant odors more irritating. Dehydration has also been demonstrated to increase nitric oxide synthase activity in the brain, which causes detrimental effects on mental performance and focus.
Inversely, sufficient water intake has been shown to improve mental focus and function, with several clinical trials providing concrete evidence that both adults and children can improve cognitive performance, neuroplasticity, reaction time, and recall. It’s clear from the evidence available that dehydration has a significant impact not only on the health of the body, but also that of the mind.
Poor mental function can occur when the body is just 2% lower in total mass due to dehydration. Ensuring you’re getting enough water is critical in promoting the long term health of your brain.
10. Serious Health Conditions
Aside from the symptoms outlined above, dehydration can cause serious health conditions if not treated immediately. Every single organ in the body requires water to function, and if hydration levels fall too low, they can shut down, creating a significant health issue.
One of the first ways in which severe dehydration can be potentially fatal is through shock. Dehydration is intrinsically linked to shock, which, left untreated, can lead to fatally low oxygen levels in the tissues of the body or heart attack. Brain damage and kidney disease also ensue from shock, and if it isn’t treated immediately, will result in death.
Organ failure, cardiac arrest and shock, however, are extremely rare symptoms of dehydration and are extremely uncommon when practicing a healthy lifestyle, typically only occurring in survival situations.
Preventing dehydration is as simple as regularly drinking water. The average human needs 15 cups of water a day, or between 2.7 and 3.7 liters, varying on sex and body size.
Foods that are rich in water content can also assist with reaching your total recommended daily intake of water. Keep in mind, however, that your fluid intake requirements will increase when performing physical activity or in warm environments, so always be sure to listen to your body and drink when thirsty.
Hydration Quick Tips:
- Listen to your body: Thirst is the most reliable indicator of hydration. Always drink when thirsty.
- Increase fluid intake during exercise: If you’re planning on performing intense physical activity, be sure to load up on water before beginning, as dehydration can occur rapidly when the body sweats.
- Observe your urine color and volume: Paying attention to the color and amount of urine your body excretes is an easy way to determine how hydrated you are. If your urine has any appearance other than almost clear, increase your water intake.
- Increase fluid intake when sick: If you’re sick, be sure to increase your fluid intake to make up for the fluids lost via vomiting and diarrhea. Fever also increases body temperature, which lowers body water content through sweating.
Dehydration Dangers Summary
Dehydration may seem like an uncommon condition that only affects people in survival situations, but is, in reality, an endemic condition that affects up to 70% of the American population. Salty foods, soda, sugary drinks and low water intake all contribute to dehydration, which has a serious and harmful effect on the body. Even low-level net fluid loss can significantly inhibit the ability of your body to metabolize food and your ability to think clearly.
Regular water consumption has been clinically proven to offer a wide range of health benefits, from enhanced metabolic function to healthier skin and increased energy levels. Water is used to flush harmful toxins from the body, so ensuring you’re getting the right amount of every day will help protect your body from disease and health disorders.
A great way to increase your total water intake is to carry a water bottle around at all times, which can be enhanced with sliced fruit, cinnamon, lemon or ginger to improve flavor. These additives have an almost neutral calorie profile and can deliver a number of bonus health effects.
If you're experiencing any of the more deleterious effects of dehydration such as abnormal heart function, dizziness, low blood pressure, or fainting, it’s critically important to consult a medical professional immediately. However, listening to your body and drinking when thirsty will go a long way in making sure you never experience the effects of severe dehydration.