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Vital signs for dehydration: Adult Dehydration – StatPearls – NCBI Bookshelf


Adult Dehydration – StatPearls – NCBI Bookshelf

Continuing Education Activity

Dehydration is a common condition that affects patients of all ages. Dehydration may complicate other medical problems and may cause significant illness. Physical examination is used to diagnose dehydration. Laboratory testing identifies the complications of dehydration. Fluid replacement is used to treat dehydration. This activity outlines the evaluation and treatment of adult dehydration and highlights the importance of the interprofessional team.


  • Identify the etiology of adult dehydration medical conditions and emergencies.

  • Review the evaluation of adult dehydration.

  • Outline the management options available for adult dehydration.

  • Describe the interprofessional team strategies for improving care coordination and communication to advance adult dehydration and improve outcomes.

Access free multiple choice questions on this topic.


According to the lay press, 75% of Americans are chronically dehydrated. While this is not supported by medical literature, dehydration is common in elderly patients. It has been reported to occur in 17% to 28% of older adults in the United States.[1] Dehydration is a frequent cause of hospital admission. It can cause morbidity and mortality on its own and complicates many medical conditions. Dehydration may also be over-diagnosed. This can lead to misdiagnosis of the real cause of the patient’s illness and lead to over-treatment with fluids. Dehydration is easily treatable and preventable. A thorough understanding of the causes and diagnosis of dehydration can improve patient care.


Body water is lost through the skin, lungs, kidneys, and GI tract. The loss of body water without sodium causes dehydration. Water is lost from the skin, lungs, gastrointestinal tract, and kidneys. Dehydration results when water losses from the body exceed water replacement. It may be caused by failure to replace obligate water losses. There are several forms of dehydration.[1] Isotonic water loss occurs when water and sodium are lost together. Causes of isotonic water loss are vomiting, diarrhea, sweating, burns, intrinsic kidney disease, hyperglycemia, and hypoaldosteronism. Hypertonic dehydration occurs when water losses exceed sodium losses. Serum sodium and osmolality will always be elevated in hypertonic dehydration. Excess pure water loss occurs through the skin, lungs, and kidneys. Etiologies are fever, increased respiration, and diabetes insipidus. Hypotonic dehydration is mostly caused by diuretics, which cause more sodium loss than water loss. Hypotonic dehydration is characterized by low sodium and osmolality.

The source of water loss may also understand the etiologies of dehydration:

  • Failure to replace water loss: altered mentation, immobility, impaired thirst mechanism, drug overdose leading to coma

  • Excess water loss from the skin: heat, exercise, burns, severe skin diseases

  • Excess water loss from the kidney: medications such as diuretics, acute and chronic renal disease, post-obstructive diuresis, salt-wasting tubular disease, Addison disease, hypoaldosteronism, hyperglycemia

  • Excess water loss from the GI tract: vomiting, diarrhea, laxatives, gastric suctioning, fistulas

  • Intraabdominal losses: pancreatitis, new ascites, peritonitis

  • Excess insensible loss: sepsis, medications, hyperthyroidism, asthma, chronic obstructive pulmonary disease (COPD), drugs


There is no recent data on rates of dehydration in the general population, but we do know much of the epidemiology of dehydration in adults. Healthy adults with access to water rarely become dehydrated. Any adult may develop dehydration as a complication of an illness such as hyperglycemia. Dehydration may cause illness or be caused by an illness, so searches of databases may not capture all cases of dehydration. The data that we do have shows that older adults are more likely to develop dehydration. The elderly population is also 20% to 30% more prone to developing dehydration due to immobility, impaired thirst mechanism, diabetes, renal disease, and falls.[2][3]


Water plays a key role in maintaining multiple physiological functions within the body. The human body is 55% to 65% of water. Two-thirds of that water is intracellular, and one-third is extracellular. One-fifth of extracellular water is intravascular. The body has a complex system designed to maintain euvolemia. Water is absorbed through the gastrointestinal tract. The primary control of water homeostasis is through osmoreceptors in the brain. As perceived by these osmoreceptors, dehydration stimulates the thirst center in the hypothalamus, which leads to water consumption. These osmoreceptors can also cause the conservation of water by the kidney. When the hypothalamus detects lower water concentration, it causes the posterior pituitary to release antidiuretic hormone (ADH), which stimulates the kidneys to reabsorb more water. Decreased blood pressure, which often accompanies dehydration, triggers renin secretion from the kidney. Renin converts angiotensin I to angiotensin II, which increases aldosterone release from the adrenals. Aldosterone increases the absorption of sodium and water from the kidney. Using these mechanisms, the body regulates body volume and sodium and water concentration.

History and Physical

Hypovolemic patients can present with a wide assortment of symptoms and physical exam findings. Some of the most common presenting symptoms of dehydration include but are not limited to fatigue, thirst, dry skin and lips, dark urine or decreased urine output, headaches, muscle cramps, lightheadedness, dizziness, syncope, orthostatic hypotension, and palpitations. The patient’s history may elicit factors that could cause dehydration, such as exercise, heat exposure, medications, illness, impaired access to water, fever, or fluid loss.

Vital signs may show hypotension, tachycardia, fever, and tachypnea. Hypotension will not appear until significant dehydration is present. Tachycardia may be absent due to medications such as beta-blockers. A patient may appear lethargic or obtunded upon observation in severe cases of dehydration. The physical examination could show dry mucosa, skin tenting, delayed capillary refill, or cracked lips. A 2015 Cochrane review evaluated predictors of dehydration in the elderly.[4] Historical and physical findings tested were dry axilla, mucous membranes, tongue, increased capillary refill time, poor skin turgor, sunken eyes, orthostatic blood pressure drop, dizziness, thirst, urine color, weakness, blue lips, altered mentation, tiredness, and appetite. Of all these factors, only fatigue and missed drinks between meals predicted the diagnosis of dehydration.


There is no gold standard test for dehydration. Serum and plasma osmolality tests are often used to diagnose but may be affected by fluid loss or fluid loss acuity. A reasonable definition of dehydration due to water loss is serum osmolality greater than or equal to 295 mOsm/kg. The 2015 Cochrane review used serum osmolality of greater than 294 mOsm/kg to define dehydration. Weight loss equal to or greater than 3% over 7 days may also indicate dehydration if this data is available. The 2015 Cochrane review of diagnostic tests for dehydration in elderly patients, bioelectrical impedance analysis, urine specific gravity, the osmolality of urine, saliva, or tears, tear volume, number of urine voids, and urine volume were not useful as stand-alone tests for dehydration in the elderly. 

Blood urea nitrogen to creatinine ratio should be higher than 10:1 in dehydration, but this may be mimicked by high urea production, low creatinine due to low muscle lass, and urea reabsorption due to upper gastrointestinal bleed. Urine tests may suggest volume depletion. Urine sodium concentration should be low, fractional excretion of sodium should be under 1%, and urine osmolality should be greater than 450 mOsm/kg. These tests of renal perception of low blood flow may also be abnormal in heart failure, cirrhosis, nephrotic syndrome, and other causes of kidney disease.

Ultrasound can be used to assess a patient’s fluid volume by measuring the collapsibility of the inferior vena cava (IVC) with respiration. A variation in the diameter of the IVC greater than 50% with respiration indicates a collapsible IVC. IVC collapse with inspiration may correlate with right atrial pressure and intravascular volume.[5] Ultrasound evaluation of the IVC may be influenced by cirrhosis, chronic heart conditions, and ventilation (spontaneous or mechanical). IVC ultrasound has limited ability to predict fluid responsiveness.[6] It may be used as part of the entire clinical picture.

Treatment / Management

Treatment of dehydration is aimed at rapid fluid replacement as well as identification of the cause of fluid loss. Patients with fluid deficits should be given isotonic fluid boluses tailored to the individual circumstance. Patients with more severe dehydration get larger boluses of isotonic fluid. A more careful approach is needed in elderly patients and patients with heart failure and kidney failure. In these patients, small boluses should be given, followed by frequent reassessment and additional bolus as needed.[7]

Blood pressure, heart rate, serum lactate, hematocrit (if bleeding, there is no blood loss), and urine output may be used to assess the volume deficit and to assess response to fluids.

Isotonic crystalloid fluid should be used in most cases of dehydration. Colloids such as albumin may be used in specific situations but do not improve outcomes.[8]

The choice of crystalloid should be customized to the patient. Normal saline lactated Ringer’s solution and a balanced crystalloid solution may all be used. Normal saline may cause hyperchloremic metabolic acidosis in large volumes. Buffered crystalloids may cause hyponatremia. Lactated Ringer’s solution also contains potassium, so it should not be used in renal failure or hyperkalemia. No fluid has proved superior in all patients.

In patients with dehydration and severe hyponatremia, rapid volume repletion may cause a rapid rise in sodium. This can cause central pontine myelinolysis (CPM). The clinician must weigh the risks of continued dehydration against the risks of CPM. The patient’s volume status and serum sodium must be followed closely.

As the patient is being resuscitated, clinical and laboratory examination must focus on the discovery and correction of the cause of dehydration.

Differential Diagnosis

The principle differential of dehydration in adults is the loss of body water versus the loss of blood. This is important because blood loss should be replaced with blood, while water loss should be replaced with fluid. The next point to consider is the differential diagnosis of the cause of dehydration, as discussed under etiology.


When the underlying cause of dehydration is treated, and the patient’s volume has been restored, the majority of patients recover fully. Failure to treat dehydration in older adults may lead to significant mortality.[9]


Complications of dehydration occur due to inadequate fluid replacement and over-aggressive fluid replacement. Complications of under-resuscitation are due to hypoperfusion of vital organs and complications due to renal efforts to retain fluid. Altered mental status, renal failure, shock liver, lactic acidosis, hypotension, and death are related to organ-hypoperfusion. Fluid and electrolyte abnormalities such as uremia, hyponatremia, hypernatremia, hypokalemia, hyperkalemia, metabolic acidosis, and metabolic alkalosis may occur. Excess fluid administration to correct dehydration may cause peripheral edema and pulmonary edema. In patients with severe hyponatremia, volume correction may cause a rapid rise in sodium, which can cause central pontine myelinolysis.  


Renal consultation will be needed at times, especially with severe hyponatremia, but in most cases, the treating clinician can evaluate and correct dehydration.

Deterrence and Patient Education

Although the CDC does not have defined water intake recommendations, adults are encouraged to maintain between 2-3 L per day. [10] Patients should be encouraged to replace their losses to keep up with activity. For example, marathon runners water should drink more than a nonmobile person. In elderly patients, excessive free water drinking can cause hyponatremia, so balanced hydration solutions are recommended.

Pearls and Other Issues

  • Because adequate volume is essential to the peak function of the human body, there are multiple mechanisms to achieve and maintain euvolemia.

  • The diagnosis of volume depletion depends on the careful assessment of physical exam, history, and laboratory tests. There is no one test to diagnose dehydration.

  • The first goal of treatment of dehydration is to restore circulating volume. The second goal is to find the cause of the dehydration so that it will not recur.

  • In patients with normal heart and renal function, liberal fluid may be given to restore volume quickly. In patients with heart failure and renal disease, volume still needs to be replaced, but a more a=careful approach is indicated. This is best accomplished with small volumes given quickly, followed by immediate reassessment and redosing as needed.

  • In severe hyponatremia, rapid correction of volume deficits may cause a sharp rise in the serum sodium that can cause central pontine myelinolysis (CPM). The clinician must assess the risks and benefits of rapid volume repletion versus the risk of CPM. In all cases, the volume status and sodium levels must be monitored closely.

Enhancing Healthcare Team Outcomes

Often because water intake is not the most pressing topic for the average clinical visit, it is often overlooked regarding patient care. If we can encourage more healthy lifestyle choices and daily hydration, it can lead to decreased morbidity, mortality, and complications associated with dehydration. Healthcare providers should look toward implementing more incentives and initiatives toward increasing hydration amongst staff and patient populations.

Review Questions

  • Access free multiple choice questions on this topic.

  • Comment on this article.



Weinberg AD, Minaker KL. Dehydration. Evaluation and management in older adults. Council on Scientific Affairs, American Medical Association. JAMA. 1995 Nov 15;274(19):1552-6. [PubMed: 7474224]


Miller HJ. Dehydration in the Older Adult. J Gerontol Nurs. 2015 Sep 01;41(9):8-13. [PubMed: 26375144]


Kayser-Jones J, Schell ES, Porter C, Barbaccia JC, Shaw H. Factors contributing to dehydration in nursing homes: inadequate staffing and lack of professional supervision. J Am Geriatr Soc. 1999 Oct;47(10):1187-94. [PubMed: 10522951]


Hooper L, Abdelhamid A, Attreed NJ, Campbell WW, Channell AM, Chassagne P, Culp KR, Fletcher SJ, Fortes MB, Fuller N, Gaspar PM, Gilbert DJ, Heathcote AC, Kafri MW, Kajii F, Lindner G, Mack GW, Mentes JC, Merlani P, Needham RA, Olde Rikkert MG, Perren A, Powers J, Ranson SC, Ritz P, Rowat AM, Sjöstrand F, Smith AC, Stookey JJ, Stotts NA, Thomas DR, Vivanti A, Wakefield BJ, Waldréus N, Walsh NP, Ward S, Potter JF, Hunter P. Clinical symptoms, signs and tests for identification of impending and current water-loss dehydration in older people. Cochrane Database Syst Rev. 2015 Apr 30;2015(4):CD009647. [PMC free article: PMC7097739] [PubMed: 25924806]


Lamarche J, Rivera AP, Courville C, Taha M, Antar-Shultz M, Reyes A. Role of Point-of-Care Ultrasonography in the Evaluation and Management of Kidney Disease. Fed Pract. 2018 Dec;35(12):27-33. [PMC free article: PMC6366586] [PubMed: 30766335]


Long E, Oakley E, Duke T, Babl FE., Paediatric Research in Emergency Departments International Collaborative (PREDICT). Does Respiratory Variation in Inferior Vena Cava Diameter Predict Fluid Responsiveness: A Systematic Review and Meta-Analysis. Shock. 2017 May;47(5):550-559. [PubMed: 28410544]


Castera MR, Borhade MB. StatPearls [Internet]. StatPearls Publishing; Treasure Island (FL): Sep 5, 2022. Fluid Management. [PubMed: 30335338]


Finfer S, Bellomo R, Boyce N, French J, Myburgh J, Norton R., SAFE Study Investigators. A comparison of albumin and saline for fluid resuscitation in the intensive care unit. N Engl J Med. 2004 May 27;350(22):2247-56. [PubMed: 15163774]


Mahowald JM, Himmelstein DU. Hypernatremia in the elderly: relation to infection and mortality. J Am Geriatr Soc. 1981 Apr;29(4):177-80. [PubMed: 7204813]


Gandy J. Water intake: validity of population assessment and recommendations. Eur J Nutr. 2015 Jun;54 Suppl 2(Suppl 2):11-6. [PMC free article: PMC4473081] [PubMed: 26048039]

Disclosure: Kory Taylor declares no relevant financial relationships with ineligible companies.

Disclosure: Elizabeth Jones declares no relevant financial relationships with ineligible companies.

Dehydration Signs, Symptoms, and Diagnosis 101

By Sheryl Huggins SalomonMedically Reviewed by Justin Laube, MD


Medically Reviewed

Fatigue, headache, and dizziness are possible symptoms of dehydration.Eva Bee/Getty Images

Water is necessary for human survival, and yet it is easy for anyone to fall behind on drinking enough. We can be depleted of body fluid by a challenging workout; hot weather; fever, vomiting, and diarrhea from an illness; and excessive urination due to a chronic illness, a medication, or too much alcohol.

The result is dehydration: the condition of losing more fluid and electrolytes than you are taking in, until you don’t have enough left for your body to function normally. (1) Knowing the signs and symptoms can help you to avoid being among the roughly half a million people who are hospitalized in the United States for dehydration each year. (2)

What Are the Early Warning Signs of Dehydration?

Alp Arkun, MD, the chief of service for emergency medicine at the Kaiser Permanente Fontana and Ontario Medical Centers in Southern California, routinely sees people who have lost enough fluid volume to merit a visit to the emergency room. But, he says, “most adults under the age of 50 have a pretty decent thirst drive. You get thirsty, you want a drink, your body corrects [its fluid balance] and life goes on.”

That thirst drive declines after age 50, putting older people at greater risk of becoming dehydrated than younger adults, Dr. Arkun says. Medications, chronic health conditions, dementia, and a decrease in fluid volume as we age can also increase the risk of dehydration in seniors. On the other end of the age spectrum, children are at higher risk for dehydration than adults because they more often have diarrhea, vomiting, and a high fever, and the youngest ones are unable to let you know they’re thirsty. (3)

Even in younger adults, the thirst drive doesn’t always push them to keep up with their fluid needs. Arkun says most will replenish with water or another beverage after experiencing one or more of these top three early warning signs:

  • Fatigue
  • Dizziness
  • Headache

“If one of those three things happens, they usually slow down doing whatever they are doing,” and drink some water, he says.

Other symptoms of dehydration include:

In Adults  (1,3,4)

  • Urinating less often than normal
  • Dark-colored urine
  • Feeling thirsty
  • Muscle cramps
  • Feeling tired or lethargic
  • Fainting
  • Confusion
  • Dry, shriveled skin
  • Constipation

In Children

When children become dehydrated, it can come on suddenly, says Arielle Levitan, MD, an internal medicine doctor at NorthShore Medical Group in Highland Park, Illinois, who owns the personalized vitamin company Vous Vitamin. “They get pretty lethargic and weak suddenly. You have to be watchful.” If you suspect dehydration in a child, one way you can tell is by pinching their skin, she adds. If it doesn’t snap back quickly, that is known as tenting, a telltale sign.

Other signs that an infant or child is dehydrated include: (3)

  • Crying without tears
  • Dry diaper after more than three hours
  • Less urination that normal
  • Dry mouth
  • Sunken eyes and cheeks
  • A sunken soft spot on top of skull
  • Irritability

How Should Early Signs of Dehydration Be Handled?

You can usually correct dehydration on your own by noticing the three early signs that Arkun mentions. If overexertion or hot weather has brought on your symptoms, remove yourself immediately from the situation, advises Kevin Coupe, MD, an orthopedic surgeon with Memorial Hermann Ironman Sports Medicine Institute and UT Physicians in the Woodlands, Texas. “If you are at an athletic event and you are burning energy, rest. Sit down, get into the shade, and drink fluid.”

Any fluid is better than none, but Coupe suggests cool water. “You don’t want it [too] cold because it doesn’t get absorbed in your stomach as quickly. Cool water is the best. Commercially available rehydration drinks such as Gatorade or Powerade are okay for the salt intake, but you do have to be careful about how much glucose, or sugar, is in them.”

Salt is a compound containing sodium and chloride, two important electrolytes (minerals that have the ability to conduct electricity in the body). Along with potassium, calcium, and sodium bicarbonate, these electrolytes are necessary for the healthy functioning of cells and tissues, as well as maintaining the right level of fluid. Dehydration can throw off the balance of electrolytes in the body. (4)

Dehydration can elevate your blood glucose level as well. If you have uncontrolled or poorly controlled diabetes, your blood sugar may already be too high. Elevated blood sugar leads to increased excretion of sugar in the urine, which pulls water along with it, thereby dehydrating you even further. Taking in a sugary solution — even if it contains important electrolytes — can worsen the problem. (5)

When Is It Time to Seek Medical Attention for Dehydration?

The truth is, you can lose 3 to 4 percent of your body’s fluid volume without experiencing any symptoms, says Arkun. After that the signs become noticeable, and you enter what medical professionals call the three stages of dehydration.  (4)

Mild (5–6 Percent of Body Fluid Lost)

This is when you experience those three early warning signs Arkun described: fatigue, dizziness, and headache. You might have a dry mouth or you may have muscle cramps, brought on by an electrolyte imbalance. Drink plain water or a sports drink immediately.

More on Dehydration Causes

How Diarrhea May Cause Dehydration

Moderate (7–10 Percent)

At this stage the loss of fluid can lead to low blood pressure and severely decreased urination. You may have a faster-than-normal pulse, or dry skin that tents when you pinch it. A child who is in this stage should receive oral hydration and medical attention. Anyone who is dehydrated and vomiting, particularly for more than four to five hours, should go to the emergency room. (4,6)

Severe (Over 10 Percent)

This stage can be life-threatening, says Arkun. Someone who is severely dehydrated is prone to fainting and injury, and electrolyte abnormalities can induce seizures. It goes without saying that someone who’s severely dehydrated needs to go to the ER. There, doctors will replenish fluids intravenously with water and sodium chloride. Death is likely if fluid loss reaches 15 to 25 percent of the person’s total body weight, he says. But this level of dehydration is rare and usually only happens if someone is isolated for an extended period of time and can’t rehydrate themselves or get help.

Still, don’t let dehydration get even to the moderate stage. Heed symptoms such as a dry mouth or a headache, and drink water, says Brian Schulz, MD, an orthopedic surgeon and sports medicine specialist at Cedars-Sinai Kerlan-Jobe Institute in Los Angeles. “Certainly anytime that someone is feeling faint, not sweating in an area in which they should be sweating, not making urine, or [if] they experience any kind of mental status changes, that is a sign they are dehydrated. If the problem doesn’t correct itself after they take in fluids, then they should pursue medical attention.”

How Will Moderate or Severe Dehydration Be Diagnosed and Treated?

In many situations, medical attention comes from a sports team medic or an emergency responder. They may ask you about your symptoms and what led to them, do a physical examination, and check your blood pressure to see if it is low. You may also be checked for a racing heartbeat or your skin may be checked for tenting. Then they may move you to a shaded area and give you water or a sports drink or, perhaps, ice chips to suck on. (2)

If the problem is severe enough to warrant an ER visit, how you’re treated will depend on the way you come in, says Sanjey Gupta, MD, the chair of emergency medicine at Southside Hospital in Bay Shore, New York. If you enter on your own two feet, that may signal that your dehydration isn’t severe. “If this is a younger person that [is] maybe a little dehydrated just because they did not drink enough when they were out running or exercising then we may actually just have them drink a sports drink or another liquid, as long as they can swallow and are not nauseous.”

Regardless of severity, the first steps toward diagnosing dehydration involve taking vital signs and a medical history. Your healthcare team may also run lab tests for electrolyte abnormalities. “If it is advanced dehydration, sometimes you’ll see that someone’s heart rate is elevated,” says Dr. Gupta. “If it’s really bad, sometimes you’ll see that their blood pressure has decreased. That might determine if an IV fluid treatment is needed, rather than giving them something to drink.”

More on Water and Your Health

Is Sparkling Water Good or Bad for Your Health?

Typically, intravenous treatment with a sodium chloride and water solution will restore a person’s fluid balance and they can return home within a few hours, Arkun says. A doctor may administer medication to control fluid-depleting symptoms such as nausea and diarrhea if there’s an underlying illness.

It’s easy to prevent dehydration. Dr. Levitan says that while looking for the signs of it are key, it’s even more important to get out ahead of it and drink enough fluid before you have any symptoms. Be aware of environmental conditions that will put you at risk, such as hot weather or dry indoor heating in the wintertime; medications and illnesses that are depleting you of fluid; or overexertion. “Be proactive. It is much better if you can think ahead and hydrate well in advance of exercising or doing something active. You’ll feel much worse if you get to that point of being dehydrated than if you just preemptively stay hydrated in the first place,” Levitan says.

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Editorial Sources and Fact-Checking

  1. Dehydration. MedlinePlus. November 13, 2018.
  2. Kim S. Preventable Hospitalizations of Dehydration: Implications of Inadequate Primary Health Care in the United States. Annals of Epidemiology. September 2007.
  3. Dehydration. Mayo Clinic.
  4. Dehydration. Gale Encyclopedia of Children’s Health: Infancy Through Adolescence. Encyclopedia.com. 2006.
  5. M Hamaty. How to Manage Your Diabetes in Extreme Summer Heat. Cleveland Clinic. May 29, 2015.
  6. Do You Know When to Visit the Hospital for Vomiting? Cleveland Clinic. July 14, 2014.

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Signs of lack of water in the body

May 4, 2023

We have already discussed the importance of drinking a daily amount of water in previous articles, and today we will discuss the signs of a dehydrated body. Depending on the volume of the body and lifestyle, a person needs to consume from 1 to 3 liters of water per day. The proper functioning of internal organs, metabolism and body temperature depend on this.

Water is a key element for maintaining human life and health. It makes up approximately 60% of an adult’s body weight and plays an important role in regulating body temperature, transporting nutrients and oxygen to cells, removing toxins from the body, and other vital functions.

Daily water intake can depend not only on body size and lifestyle, but also on environmental conditions, physical activity level, nutrition and other factors. For example, in hot weather or during physical activity, you need to drink more water to compensate for the loss of fluid through sweat.

Regular consumption of coffee, tea, and other caffeinated beverages can increase fluid excretion from the body and impair hydration. However, many foods, such as fruits and vegetables, also contain significant amounts of water and can help meet your daily fluid requirement.

When we are thirsty, our body signals a lack of fluid with dry mouth, high blood pressure, and sometimes even dizziness. However, situations are possible when instead of pure water we drink tea or coffee, disrupting metabolic processes in the body and increasing the amount of toxins. Due to the fact that the body gets used to a smaller volume of water, we do not always notice the symptoms of dehydration. But there are certain signs, such as dry skin and mucous membranes, dark urine, weakness and drowsiness, which signal us about a lack of fluid in the body.

Regular heartburn can be a symptom of dehydration. Drink more water to reduce the increased acidity in your stomach. If heartburn happens from time to time, then it is hardly worth worrying about it. Most likely, it appeared for other reasons.

Blood pressure rises. Why is this happening? Due to the lack of fluid in the body, the blood becomes thick and moves poorly through the vessels. A glass of drinking water will help you return the pressure to normal.

Another sure sign of dehydration is tight, dry skin that flakes off. Drink enough fluids to prevent this from happening.

All these signs are very unpleasant. They most accurately signal us about dehydration. How much water do you need to drink to avoid such problems?
It all depends on your body weight. If you weigh about 40 kg, drink 1 liter of water. 60 kg – 1.5 liters of water per day. If your whole is about 80 kg, then you need to drink 2. 5 liters of water per day. With a weight of 100 kg, drink up to 3 liters. You can use a special application or a calendar where you can mark the amount of water you drink.

Start a new day with a glass of clean water without gas. It will help you wake up faster and start the digestive tract. Drink the right amount of water throughout the day. Your body will get used to the amount of fluid and will itself remind you of the need to replenish the water balance.

Dehydration can lead to serious health problems, including kidney, liver and heart problems, and damage to cells and tissues. Therefore, it is necessary to monitor the use of sufficient amounts of water and react in time to signs of dehydration.

symptoms, causes, complications, treatments

  1. How dehydration occurs
  2. Causes of dehydration
  3. Additional factors
  4. What happens when you get dehydrated
  5. Dewatering types
  6. Symptoms
  7. Diagnostics
  8. Treatment for dehydration
  9. Prophylaxis
  10. Making a rehydrating solution at home

Image by Freepik

Dehydration is a state of increased loss of moisture from the body. Otherwise, this condition is called dehydration or exsicosis. It is characterized by thirst, dry skin, decreased urine output. As the moisture deficit increases, the patient’s blood pressure decreases, the skin becomes pale, there are disturbances in consciousness, pathological changes in the blood composition – an increase in hematocrit. This is the name for an increase in the volume of red blood cells relative to the volume of the liquid part of the blood.

Dehydration is a dangerous condition in which the body needs an urgent restoration of water and electrolyte balance.

How dehydration occurs

Dehydration occurs when the liquid drops to 40–50 ml/kg. In this case, body weight decreases by 4-5% due to the loss of water. In the body, it is found in the blood, cells of organs and tissues, and intercellular space. If water loss as a result of exsicosis reaches 20-25%, tissue ischemia begins – a violation of the blood supply to organs and tissues due to an increase in hematocrit.

Causes of dehydration

Exicosis most often occurs against the background of various diseases and pathological conditions. Among them:

  • intestinal infections that cause vomiting and upset stools;

  • burns of the second or more degree, in which there is an extensive release of exudate;

  • diseases that are accompanied by fever and increased sweating;

  • insufficient fluid intake with food;

  • diseases accompanied by shortness of breath, in which the body loses moisture due to the release of water vapor.

The most common cause of dehydration is intestinal infections. Up to 48% of all clinical cases of exsicosis are associated with such diseases. They pose the greatest danger to young children. Frequent vomiting and loose stools lead to rapid loss of moisture, which causes dehydration. In countries with a low standard of living and a high incidence of intestinal infections, excoses are one of the main causes of death in young children under the age of 5–6 years.

With extensive burns, a large amount of exudate is released. If the patient does not receive fluid replacement therapy, a fluid deficiency develops.

Increased sweating at elevated body temperature requires control of the drinking regimen. This is especially important if the patient is in a warm room.

Insufficient fluid intake with meals can lead to dehydration if a person voluntarily or deliberately restricts drinking. About one and a half liters of water the body loses per day with sweat, defecation and urination. If the fluid intake is below normal, exsicosis develops.

Dehydration associated with shortness of breath occurs in patients with respiratory and cardiac pathologies. This phenomenon in healthy people is observed when traveling to high mountainous areas due to changes in the composition of the air.

Additional factors

Even healthy people who live in hot regions, do intensive sports or physical labor in hot weather, and stay in the mountains face a moisture deficiency in the body. To avoid dehydration, it is necessary to consume enough water, fresh vegetables and fruits.

Patients taking diuretics and people on mechanical ventilation are also at risk. To prevent exsicosis, patients on mechanical ventilation are injected with saline solutions and moisten the respiratory mixture that enters the body.

What happens when you get dehydrated

When the body loses a lot of moisture, blood viscosity changes first of all. It increases against the background of a decrease in plasma volume. This negatively affects the blood supply to organs and tissues, including the brain. Dehydration leads to an electrolyte imbalance, a decrease in the amount of mineral salts. A decrease in the concentration of potassium, calcium and sodium ions leads to disruption in the work of the heart.

A patient with severe dehydration has acidosis, which is characterized by an acid-base imbalance. The pH formula shifts to the acid side. This leads to repeated vomiting, after which the person develops metabolic alkalosis. It is manifested by various disorders in the work of the respiratory and cardiovascular systems.

Dewatering types

The classification of exicoses includes their division into several groups depending on the severity of the course, the cause of the development of the pathology, the presence or absence of complications.

The severity of dehydration is mild, moderate and severe. It can be caused by external and internal causes, pass with complications and without them.

When choosing therapy, experts pay attention to the ratio of the loss of mineral salts and water. On this basis, three forms of dehydration are distinguished:

  • hypoosmolar. It is characterized by a rapid loss of salts with a slow development of water deficiency. This leads to the rapid onset of negative symptoms from the central nervous system. The patient’s blood circulation is disturbed, signs of a neurological disorder appear;

  • hyperosmolar. Fluid loss occurs faster than electrolyte loss. Due to this, their concentration increases. With this kind of dehydration, pronounced symptoms appear only with a significant deficit of moisture;

  • isosmolar. The loss of water and salts is about the same. The patient has a decrease in the amount of urine excreted, may decrease blood pressure (BP) and central venous pressure.


Each degree of dehydration is characterized by special signs:

  • mild degree. The patient is thirsty, the pulse remains normal, may become more frequent. Skin and mucous membranes are unchanged. On the part of the nervous system, there may be signs of anxiety and anxiety;

  • average degree. Externally, the pathology is manifested by dry skin and mucous membranes, a decrease in diuresis. The eyes become sunken, the patient’s pulse quickens, the pressure is increased or decreased by about 20% of the usual values. From the side of the central nervous system, both anxiety and lethargy can be observed;

  • severe degree. Pronounced fluid deficiency causes neurological disorders. The patient is very lethargic and practically does not react to anything. Breathing becomes difficult, blood pressure is greatly reduced, tachycardia is characteristic. The skin looks pale and has a bluish tint, it is cold to the touch.

Moderate to severe dehydration increases the risk of complications. First of all, they are associated with the formation of blood clots due to the high viscosity of the blood. When a thrombus clogs the vessels of vital organs, the patient may die or receive irreversible negative changes. Some people who survive severe dehydration develop chronic headaches, weakness, and reduced muscle mobility. Children have cognitive impairment.


At the first signs of dehydration, it is necessary to contact a medical institution to a general practitioner, a general practitioner, a pediatrician. If dehydration is severe, an ambulance must be called to hospitalize the patient in a medical facility.

For the diagnosis of exicosis, the following are used:

  • visual examination and questioning of the patient for the presence of vomiting, diarrhea;

  • measurement of arterial and central venous pressure;

  • blood test for electrolytes and hematocrit.

A decrease in central venous pressure and an increase in hematocrit above the age norm indicate fluid deficiency.

Treatment for dehydration

With mild dehydration, the patient is treated at home. With moderate and severe fluid deficiency, which are accompanied by changes in the central nervous system, circulatory disorders, hospitalization and intensive treatment are necessary.

The main ways to eliminate exsicosis are:

  • the use of rehydrating solutions or large amounts of liquid with the addition of salt to restore water and electrolyte balance;

  • intravenous infusion of glucose and saline solutions. It is used in conditions that are accompanied by severe vomiting. Fluid therapy will make up for the lack of fluid if the patient cannot drink it by mouth due to frequent vomiting.

Severe dehydration may require intensive care with a ventilator. With signs of tissue ischemia, neuroprotectors, potassium preparations, drugs to maintain the work of the heart are prescribed.

Treatment is continued until normalization of blood circulation and diuresis. To achieve stable results, it is important to identify the exact cause of the pathological condition and eliminate it.

As a rule, with a slight dehydration, it is possible to completely normalize the patient’s condition within 1-2 days. In moderate and severe dehydration, the prognosis depends on the severity. In some cases, the risk of developing serious violations of body functions, up to irreversible processes, increases.


To avoid dehydration, you need to know what factors provoke it, and take appropriate safety measures. This is, first of all, adequate intake of water and fluids. Its volume is from 1.5 liters per day and increases with intense physical exertion, in hot weather.

If the patient has diarrhea or vomiting, rehydration solutions should be used to prevent dehydration. You can buy them at a pharmacy or make your own at home. Pharmacy rehydrating solutions contain potassium chloride, sodium chloride and other mineral salts.

The funds are available in the form of a powder that dissolves in water and is taken orally to prevent water and electrolyte disorders. Powders contain flavoring additives, due to which the use of the drug does not cause discomfort in adults and children.

In addition to powders, rehydrating agents are available as infusion solutions.

Making a rehydrating solution at home

If it is not possible to buy a pharmacy product, it can be seen as a home analogue. To prepare the drink, you need a tablespoon of salt, a teaspoon of soda and two tablespoons of sugar.