For this reason, the urine becomes more concentrated with waste products from the body, like sodium and urea 7. The goal is not to have completely clear urine. Instead, the ideal urine color is a pale yellow, like the color of light straw. Keep in mind that other factors can affect your urine color, including the use of medications and B vitamins, which can turn urine bright yellow.

One of the most common signs of dehydration is dry skin and lips and decreased skin elasticity 8. The skin turgor test involves grasping the skin on the lower arm or abdomen between two fingers and then releasing it after a few seconds. Decreased skin turgor is usually a sign of moderate to severe dehydration 9.

One theory is that fluid depletion in the body leads to the stretching of blood channels in the brain, leading to headaches 10 , However, researchers acknowledge that there are likely multiple mechanisms behind dehydration-related headaches , and that some people may be more susceptible to dehydration-related headaches than others Some studies show that increasing water intake may help reduce headache symptoms in people who experience migraine.

One study that included women with migraine headaches showed that migraine severity, frequency, and duration were significantly lower in those who drank more water Dehydration may cause you to feel dizzy and light-headed, especially when you stand up Orthostatic hypotension is the medical term for a reduction in blood pressure when you stand or sit up Dehydration can lead to orthostatic hypotension.

This is especially common among older adults, who are more at risk of developing dehydration and low blood volume hypovolemia Being dehydrated may cause you to feel dizzy and light-headed, especially when you stand or sit up quickly.

Severe dehydration may even lead to fainting in some cases, especially among older adults Being dehydrated may cause cardiac symptoms like palpitations , or a sensation of pounding, fluttering, or an irregular heartbeat 2. According to one review, dehydration may impair heart function in several ways, including by negatively affecting blood vessel function and altering blood pressure regulation Dehydration can also compromise heart function in people who are performing intense exercise in the heat.

It does this by decreasing the amount of blood pumped out of the left ventricle of the heart and reducing cardiac output — the amount of blood the heart pumps per minute Low blood pressure is a sign of dehydration that only appears if a person is significantly dehydrated.

As mentioned above, dehydration impairs blood vessel function and blood pressure regulation. Dehydration causes low blood volume — that is, a low amount of fluid circulating within your capillaries, veins, arteries, and chambers of your heart When your blood volume decreases, your body compensates by increasing your pulse and respiratory rate, as well as by decreasing your blood pressure Low blood pressure is a sign of severe dehydration, and it can be dangerous.

Severe dehydration could lead to significantly low blood pressure, shock, and even death Not taking in enough fluids can take a toll on your brain and reduce your ability to concentrate.

Some studies have shown that dehydration can be detrimental to short-term memory, concentration, and mood. A small study including 12 men found that abstaining from drinking water for 36 hours led to higher error rates on tests and negatively affected energy, mood, attention, and memory.

Rehydration with water alleviated these symptoms Many other studies have also shown that dehydration can negatively affect mood and cognitive performance in both men and women 22 , Severe dehydration can lead to an altered mental state, which can seem like confusion and anger Many signs and symptoms may indicate dehydration in adults, including dark-colored urine, decreased urination, headaches, fatigue, dry skin, and light-headedness.

A dehydrated infant or child may not show the same signs of dehydration that adults do, making it hard for parents and caregivers to identify potential dehydration. Dehydration can be mild, moderate, or severe, based on how much of your body's fluid is lost or not replaced.

Severe dehydration is a life-threatening emergency. A decrease in skin turgor is indicated when the skin on the back of the hand for an adult or on the abdomen for a child is pulled up for a few seconds and does not return to its original state. A decrease in skin turgor is a late sign of dehydration.

You can become dehydrated if you lose too much fluid, do not drink enough water or fluids, or both. Older adults and people with certain diseases, such as diabetes, are also at higher risk for dehydration. For more severe dehydration or heat emergency , you may need to stay in a hospital and receive fluid through a vein IV.

The provider will also treat the cause of the dehydration. Dehydration caused by a stomach or intestinal virus should get better on its own after a few days. Kenefick RW, Cheuvront SN, Leon LR, O'Brien KK. Dehydration and rehydration. In: Auerbach PS, Cushing TA, Harris NS, eds. Auerbach's Wilderness Medicine.

Philadelphia, PA: Elsevier; chap Padlipsky P, White W. Pediatric infectious diarrheal disease and dehydration. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. Reviewed by: Neil K. Kaneshiro, MD, MHA, Clinical Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA.

The feeling of thirst is the result of a complex physiological process, research shows , intended as a warning that you're dehydrated, and in danger of not functioning properly. As MedlinePlus points out, certain health conditions, including diabetes, can put you at an increased risk of dehydration.

People who are especially vulnerable to dehydration include those who are unable to quench their thirst because of disability or disease, athletes, and those who are simply too young or too old to replace lost fluids on their own, according to NHS Inform. Men who are middle-aged or elderly may be at particular risk of complications from dehydration, according to a small study published in the Journal of Physiology in November The study did not involve women.

The researchers found that over time, the body becomes worse at detecting markers of dehydration such as high levels of salt in the blood , and without these signals, older adults may not realize they are dehydrated or drink fluids to rehydrate.

Untreated dehydration can cause the heart rate to increase, straining your ticker. Extreme dehydration — defined by the World Health Organization as a loss of more than 10 percent of your body weight in fluid — can lead to injury or fatal complications, and it requires an ER visit.

Seizures, cardiac arrhythmia , or hypovolemic shock can occur because your blood volume is too low. Yet it rarely comes to that. Most of the time, you can easily replenish your fluid stores and fend off dehydration when you drink water throughout the day.

Here are six surprising signs and symptoms of dehydration. Saliva has antibacterial properties, but dehydration can prevent your body from making enough saliva, per the Better Health Channel. Johnson General Hospital. So the next time you experience dry mouth and your breath smells less than fresh, it may be time to rehydrate.

Higgins says, adding that skin may appear flushed as well. Another key skin-related symptom of dehydration is a loss of skin elasticity, according to MedlinePlus.

One symptom to watch for is muscle cramps, which can happen during exercise, particularly in hot weather. As the muscles work harder and harder, they can seize up from the heat itself.

Bear in mind that when it comes to rehydration after exercise, all drinks may not be created equal. A study published in March in BMJ Open Sport and Exercise Medicine found that when participants rehydrated with a drink containing electrolytes after exercise, they were less likely to develop muscle cramps.

Participants who drank plain water, on the other hand, were more likely to have cramps. The study was small, so its findings may not apply to you, but the next time you feel a muscle cramp coming on after exercise, opt for an electrolyte-filled sports drink. Higgins says symptoms may be milder or come on slower, but dehydration carries the same risks, regardless of the temperature outside.

Other symptoms of heat illness include fever and chills. Excessive sweating combined with your skin feeling cool to the touch may be signs of heat exhaustion, according to the Centers for Disease Control and Prevention CDC.

Fever can worsen dehydration. The higher the fever, the more severely dehydrated you may become. Unless your body temperature decreases, your skin will lose its cool clamminess and then become hot, flushed, and dry to the touch.

Applying ice and cool, wet cloths, and moving to a cool area are short-term strategies until you can get medical attention.