Dehydration

Last updated

Dehydration
Cholera rehydration nurses.jpg
Nurses encourage a patient to drink an oral rehydration solution to treat the combination of dehydration and hypovolemia secondary to cholera. Cholera leads to GI loss of both excess free water (dehydration) and sodium (hence ECF volume depletion—hypovolemia).
Specialty Critical care medicine
Symptoms Increased thirst, tiredness, decreased urine, dizziness, headaches, and confusion [1]
Complications Low blood volume shock (hypovolemic shock), coma, seizures, urinary tract infection, kidney disease, heatstroke, hypernatremia, metabolic disease, [1] hypertension. [2]
CausesLoss of body water
Risk factors Physical water scarcity, heatwaves, disease (most commonly from diseases that cause vomiting and/or diarrhea), exercise
TreatmentDrinking clean water
Medication Saline

In physiology, dehydration is a lack of total body water, [3] with an accompanying disruption of metabolic processes. It occurs when free water loss exceeds free water intake, usually due to exercise, disease, or high environmental temperature. Mild dehydration can also be caused by immersion diuresis, which may increase risk of decompression sickness in divers.

Contents

Most people can tolerate a 3-4% decrease in total body water without difficulty or adverse health effects. A 5-8% decrease can cause fatigue and dizziness. Loss of over 10% of total body water can cause physical and mental deterioration, accompanied by severe thirst. Death occurs at a loss of between 15 and 25% of the body water. [4] Mild dehydration is characterized by thirst and general discomfort and is usually resolved with oral rehydration.

Dehydration can cause hypernatremia (high levels of sodium ions in the blood) and is distinct from hypovolemia (loss of blood volume, particularly blood plasma).

Chronic dehydration can contribute to the formation of kidney stones as well as the development of chronic kidney disease. [5] [6]

Signs and symptoms

Urine color as an indicator of hydration Urine Hydration chart.svg
Urine color as an indicator of hydration
Ultrasound of the blood vessels of the neck that supports the diagnosis of severe dehydration [8]

The hallmarks of dehydration include thirst and neurological changes such as headaches, general discomfort, loss of appetite, nausea, decreased urine volume (unless polyuria is the cause of dehydration), confusion, unexplained tiredness, purple fingernails, and seizures. [9] The symptoms of dehydration become increasingly severe with greater total body water loss. A body water loss of 1-2%, considered mild dehydration, is shown to impair cognitive performance. [10] While in people over age 50, the body's thirst sensation diminishes with age, a study found that there was no difference in fluid intake between young and old people. [11] Many older people have symptoms of dehydration. Dehydration contributes to morbidity in the elderly population, especially during conditions that promote insensible free water losses, such as hot weather. A Cochrane review on this subject defined water-loss dehydration as "people with serum osmolality of 295 mOsm/kg or more" and found that the main symptom in the elderly (people aged over 65) was fatigue.[ clarification needed ] [12]

Cause

Risk factors for dehydration include but are not limited to: exerting oneself in hot and humid weather, habitation at high altitudes, endurance athletics, elderly adults, infants, children and people living with chronic illnesses. [13]

Dehydration can also come as a side effect from many different types of drugs and medications. [14]

In the elderly, blunted response to thirst or inadequate ability to access free water in the face of excess free water losses (especially hyperglycemia related) seem to be the main causes of dehydration. [15] Excess free water or hypotonic water can leave the body in two ways – sensible loss such as osmotic diuresis, sweating, vomiting and diarrhea, and insensible water loss, occurring mainly through the skin and respiratory tract. In humans, dehydration can be caused by a wide range of diseases and states that impair water homeostasis in the body. These occur primarily through either impaired thirst/water access or sodium excess. [16]

Diagnosis

Definition

Dehydration occurs when water intake does not replace free water lost due to normal physiologic processes, including breathing, urination, perspiration, or other causes, including diarrhea, and vomiting. Dehydration can be life-threatening when severe and lead to seizures or respiratory arrest, and also carries the risk of osmotic cerebral edema if rehydration is overly rapid. [17]

The term "dehydration" has sometimes been used incorrectly as a proxy for the separate, related condition of hypovolemia, which specifically refers to a decrease in volume of blood plasma. [3] The two are regulated through independent mechanisms in humans; [3] the distinction is important in guiding treatment. [18]

Physical Examination

The skin turgor test can be used to support the diagnosis of dehydration. The skin turgor test is conducted by pinching skin on the patients patient's forearm for example, and watching to see how quickly it returns to its normal position. The skin turgor test can be unrelaible in patients how have reduced skin elasticity, such as the elderly. [19]

Prevention

For routine activities, thirst is normally an adequate guide to maintain proper hydration. [20] Minimum water intake will vary individually depending on weight, energy expenditure, age, sex, physical activity, environment, diet, and genetics. [21] [22] With exercise, exposure to hot environments, or a decreased thirst response, additional water may be required. In athletes in competition, drinking to thirst optimizes performance and safety, despite weight loss, and as of 2010, there was no scientific study showing that it is beneficial to stay ahead of thirst and maintain weight during exercise. [23]

In warm or humid weather, or during heavy exertion, water loss can increase markedly, because humans have a large and widely variable capacity for sweating. Whole-body sweat losses in men can exceed 2 L/h during competitive sport, with rates of 3–4 L/h observed during short-duration, high-intensity exercise in the heat. [24] When such large amounts of water are being lost through perspiration, electrolytes, especially sodium, are also being lost.[ citation needed ]

In most athletes exercising and sweating for 4–5 hours with a sweat sodium concentration of less than 50 mmol/L, the total sodium lost is less than 10% of total body stores (total stores are approximately 2,500 mmol, or 58 g for a 70-kg person). [25] These losses appear to be well tolerated by most people. The inclusion of sodium in fluid replacement drinks has some theoretical benefits [25] and poses little or no risk, so long as these fluids are hypotonic (since the mainstay of dehydration prevention is the replacement of free water losses).

Treatment

The most effective treatment for minor dehydration is widely considered to be drinking water and reducing fluid loss. Plain water restores only the volume of the blood plasma, inhibiting the thirst mechanism before solute levels can be replenished. [26] Solid foods can contribute to replace fluid loss from vomiting and diarrhea. [27] Urine concentration and frequency will return to normal as dehydration resolves. [28]

In some cases, correction of a dehydrated state is accomplished by the replenishment of necessary water and electrolytes (through oral rehydration therapy, or fluid replacement by intravenous therapy). As oral rehydration is less painful, non-invasive, inexpensive, and easier to provide, it is the treatment of choice for mild dehydration.[ citation needed ] Solutions used for intravenous rehydration must be isotonic or hypertonic.[ citation needed ] Pure water injected into the veins will cause the breakdown (lysis) of red blood cells (erythrocytes).[ citation needed ]

When fresh water is unavailable (e.g. at sea or in a desert), seawater or drinks with significant alcohol concentration will worsen dehydration. Urine contains a lower solute concentration than seawater; this requires the kidneys to create more urine to remove the excess salt, causing more water to be lost than was consumed from seawater. [29] If a person is dehydrated and taken to a medical facility, IVs can also be used. [30] [31] [32] [33]

For severe cases of dehydration where fainting, unconsciousness, or other severely inhibiting symptoms are present (the patient is incapable of standing upright or thinking clearly), emergency attention is required. Fluids containing a proper balance of replacement electrolytes are given orally or intravenously with continuing assessment of electrolyte status; complete resolution is normal in all but the most extreme cases. [34]

See also

Related Research Articles

<span class="mw-page-title-main">Diabetes insipidus</span> Condition characterized by large amounts of dilute urine and increased thirst

Diabetes insipidus (DI), alternately called arginine vasopressin deficiency (AVP-D) or arginine vasopressin resistance (AVP-R), is a condition characterized by large amounts of dilute urine and increased thirst. The amount of urine produced can be nearly 20 liters per day. Reduction of fluid has little effect on the concentration of the urine. Complications may include dehydration or seizures.

<span class="mw-page-title-main">Drinking</span> Ingestion of water or other liquids

Drinking is the act of ingesting water or other liquids into the body through the mouth, proboscis, or elsewhere. Humans drink by swallowing, completed by peristalsis in the esophagus. The physiological processes of drinking vary widely among other animals.

Hyponatremia or hyponatraemia is a low concentration of sodium in the blood. It is generally defined as a sodium concentration of less than 135 mmol/L (135 mEq/L), with severe hyponatremia being below 120 mEq/L. Symptoms can be absent, mild or severe. Mild symptoms include a decreased ability to think, headaches, nausea, and poor balance. Severe symptoms include confusion, seizures, and coma; death can ensue.

<span class="mw-page-title-main">Fluid replacement</span>

Fluid replacement or fluid resuscitation is the medical practice of replenishing bodily fluid lost through sweating, bleeding, fluid shifts or other pathologic processes. Fluids can be replaced with oral rehydration therapy (drinking), intravenous therapy, rectally such as with a Murphy drip, or by hypodermoclysis, the direct injection of fluid into the subcutaneous tissue. Fluids administered by the oral and hypodermic routes are absorbed more slowly than those given intravenously.

<span class="mw-page-title-main">Sports drink</span> Oral electrolytic infusion

Sports drinks, also known as electrolyte drinks, are functional beverages whose stated purpose is to help athletes replace water, electrolytes, and energy before, during and especially after training or competition. The evidence is lacking pertaining to the efficacy of use of commercial sports drinks for sports and fitness performance.

Polydipsia is excessive thirst or excess drinking. The word derives from the Greek πολυδίψιος (poludípsios) "very thirsty", which is derived from πολύς + δίψα. Polydipsia is a nonspecific symptom in various medical disorders. It also occurs as an abnormal behaviour in some non-human animals, such as in birds.

<span class="mw-page-title-main">Electrolyte imbalance</span> Medical condition

Electrolyte imbalance, or water-electrolyte imbalance, is an abnormality in the concentration of electrolytes in the body. Electrolytes play a vital role in maintaining homeostasis in the body. They help to regulate heart and neurological function, fluid balance, oxygen delivery, acid–base balance and much more. Electrolyte imbalances can develop by consuming too little or too much electrolyte as well as excreting too little or too much electrolyte. Examples of electrolytes include calcium, chloride, magnesium, phosphate, potassium, and sodium.

Hypernatremia, also spelled hypernatraemia, is a high concentration of sodium in the blood. Early symptoms may include a strong feeling of thirst, weakness, nausea, and loss of appetite. Severe symptoms include confusion, muscle twitching, and bleeding in or around the brain. Normal serum sodium levels are 135–145 mmol/L. Hypernatremia is generally defined as a serum sodium level of more than 145 mmol/L. Severe symptoms typically only occur when levels are above 160 mmol/L.

Hyperchloremia is an electrolyte disturbance in which there is an elevated level of chloride ions in the blood. The normal serum range for chloride is 96 to 106 mEq/L, therefore chloride levels at or above 110 mEq/L usually indicate kidney dysfunction as it is a regulator of chloride concentration. As of now there are no specific symptoms of hyperchloremia; however, it can be influenced by multiple abnormalities that cause a loss of electrolyte-free fluid, loss of hypotonic fluid, or increased administration of sodium chloride. These abnormalities are caused by diarrhea, vomiting, increased sodium chloride intake, renal dysfunction, diuretic use, and diabetes. Hyperchloremia should not be mistaken for hyperchloremic metabolic acidosis as hyperchloremic metabolic acidosis is characterized by two major changes: a decrease in blood pH and bicarbonate levels, as well as an increase in blood chloride levels. Instead those with hyperchloremic metabolic acidosis are usually predisposed to hyperchloremia.

<span class="mw-page-title-main">Water intoxication</span> Potentially fatal overhydration

Water intoxication, also known as water poisoning, hyperhydration, overhydration, water toxemia or hyponatremia is a potentially fatal disturbance in brain functions that can result when the normal balance of electrolytes in the body is pushed outside safe limits by excessive water intake.

<span class="mw-page-title-main">Oral rehydration therapy</span> Type of fluid replacement used to prevent and treat dehydration

Oral rehydration therapy (ORT) is a type of fluid replacement used to prevent and treat dehydration, especially due to diarrhea. It involves drinking water with modest amounts of sugar and salts, specifically sodium and potassium. Oral rehydration therapy can also be given by a nasogastric tube. Therapy can include the use of zinc supplements to reduce the duration of diarrhea in infants and children under the age of 5. Use of oral rehydration therapy has been estimated to decrease the risk of death from diarrhea by up to 93%.

Fluid balance is an aspect of the homeostasis of organisms in which the amount of water in the organism needs to be controlled, via osmoregulation and behavior, such that the concentrations of electrolytes in the various body fluids are kept within healthy ranges. The core principle of fluid balance is that the amount of water lost from the body must equal the amount of water taken in; for example, in humans, the output must equal the input. Euvolemia is the state of normal body fluid volume, including blood volume, interstitial fluid volume, and intracellular fluid volume; hypovolemia and hypervolemia are imbalances. Water is necessary for all life on Earth. Humans can survive for 4 to 6 weeks without food but only for a few days without water.

Nephrogenic diabetes insipidus, recently renamed as arginine vasopressin resistance (AVP-R) and also previously known as renal diabetes insipidus, is a form of diabetes insipidus primarily due to pathology of the kidney. This is in contrast to central or neurogenic diabetes insipidus, which is caused by insufficient levels of vasopressin. Nephrogenic diabetes insipidus is caused by an improper response of the kidney to vasopressin, leading to a decrease in the ability of the kidney to concentrate the urine by removing free water.

Phosphate nephropathy or nephrocalcinosis is an adverse renal condition that arises with a formation of phosphate crystals within the kidney's tubules. This renal insufficiency is associated with the use of oral sodium phosphate (OSP) such as C.B. Fleet's Phospho soda and Salix's Visocol, for bowel cleansing prior to a colonoscopy.   

<span class="mw-page-title-main">Urine specific gravity</span> Topic related to human medicine

Specific gravity, in the context of clinical pathology, is a urinalysis parameter commonly used in the evaluation of kidney function and can aid in the diagnosis of various renal diseases.

<span class="mw-page-title-main">Sodium in biology</span> Use of Sodium by organisms

Sodium ions are necessary in small amounts for some types of plants, but sodium as a nutrient is more generally needed in larger amounts by animals, due to their use of it for generation of nerve impulses and for maintenance of electrolyte balance and fluid balance. In animals, sodium ions are necessary for the aforementioned functions and for heart activity and certain metabolic functions. The health effects of salt reflect what happens when the body has too much or too little sodium. Characteristic concentrations of sodium in model organisms are: 10 mM in E. coli, 30 mM in budding yeast, 10 mM in mammalian cell and 100 mM in blood plasma.

<span class="mw-page-title-main">Management of dehydration</span>

Dehydration can occur as a result of diarrhea, vomiting, water scarcity, physical activity, and alcohol consumption. Management of dehydration seeks to reverse dehydration by replenishing the lost water and electrolytes. Water and electrolytes can be given through a number of routes, including oral, intravenous, and rectal.

<span class="mw-page-title-main">Adipsia</span> Medical condition

Adipsia, also known as hypodipsia, is a symptom of inappropriately decreased or absent feelings of thirst. It involves an increased osmolality or concentration of solute in the urine, which stimulates secretion of antidiuretic hormone (ADH) from the hypothalamus to the kidneys. This causes the person to retain water and ultimately become unable to feel thirst. Due to its rarity, the disorder has not been the subject of many research studies.

Exercise-associated hyponatremia (EAH) is a fluid-electrolyte disorder caused by a decrease in sodium levels (hyponatremia) during or up to 24 hours after prolonged physical activity. This disorder can develop when marathon runners or endurance event athletes drink more fluid, usually water or sports drinks, than their kidneys can excrete. This excess water can severely dilute the level of sodium in the blood needed for organs, especially the brain, to function properly.

<span class="mw-page-title-main">Salt poisoning</span> Medical condition

Salt poisoning is an intoxication resulting from the excessive intake of sodium in either solid form or in solution. Salt poisoning sufficient to produce severe symptoms is rare, and lethal salt poisoning is possible but even rarer. The lethal dose of table salt is roughly 0.5–1g per kg of body weight.

References

  1. 1 2 "Dehydration - Symptoms and causes". Mayo Clinic.
  2. ↑ Ahmed M. El-Sharkawy; Opinder Sahota; Dileep N. Lobo. "Acute and chronic effects of hydration status on health". academic.oup.com. Retrieved August 9, 2022.
  3. 1 2 3 Mange K, Matsuura D, Cizman B, Soto H, Ziyadeh FN, Goldfarb S, Neilson EG (November 1997). "Language guiding therapy: the case of dehydration versus volume depletion". Annals of Internal Medicine. 127 (9): 848–53. doi:10.7326/0003-4819-127-9-199711010-00020. PMID   9382413. S2CID   29854540.
  4. ↑ Ashcroft F, Life Without Water in Life at the Extremes. Berkeley and Los Angeles, 2000, 134-138.
  5. ↑ Seal, Adam D.; Suh, Hyun-Gyu; Jansen, Lisa T.; Summers, LynnDee G.; Kavouras, Stavros A. (2019). "Hydration and Health". Analysis in Nutrition Research. Elsevier. pp. 299–319. doi:10.1016/b978-0-12-814556-2.00011-7. ISBN   978-0-12-814556-2.
  6. ↑ Clark, William F.; Sontrop, Jessica M.; Huang, Shi-Han; Moist, Louise; Bouby, Nadine; Bankir, Lise (2016). "Hydration and Chronic Kidney Disease Progression: A Critical Review of the Evidence". American Journal of Nephrology. 43 (4): 281–292. doi: 10.1159/000445959 . ISSN   0250-8095.
  7. ↑ "Urine colour chart". Healthdirect Australia . January 2024.
  8. ↑ "UOTW#59 - Ultrasound of the Week". Ultrasound of the Week. September 23, 2015. Retrieved May 27, 2017.
  9. ↑ The Handbook Of The SAS And Elite Forces. How The Professionals Fight And Win. Edited by Jon E. Lewis. p.426-Tactics And Techniques, Survival. Robinson Publishing Ltd 1997. ISBN   1-85487-675-9
  10. ↑ Riebl SK, Davy BM (November 2013). "The Hydration Equation: Update on Water Balance and Cognitive Performance". ACSM's Health & Fitness Journal. 17 (6): 21–28. doi:10.1249/FIT.0b013e3182a9570f. PMC   4207053 . PMID   25346594.
  11. ↑ Hall, Harriet (August 17, 2020). "Are You Dehydrated?". Skeptical Inquirer. 4 (4).
  12. ↑ Hooper L, Abdelhamid A, Attreed NJ, Campbell WW, Channell AM, Chassagne P, et al. (April 2015). "Clinical symptoms, signs and tests for identification of impending and current water-loss dehydration in older people". The Cochrane Database of Systematic Reviews. 4 (4): CD009647. doi:10.1002/14651858.CD009647.pub2. hdl: 2066/110560 . PMC   7097739 . PMID   25924806.
  13. ↑ "Dehydration Risk factors - Mayo Clinic". www.mayoclinic.org. Retrieved December 14, 2015.
  14. ↑ "Types of Drugs and Medications That Can Cause Dehydration". WebMD.
  15. ↑ Borra SI, Beredo R, Kleinfeld M (March 1995). "Hypernatremia in the aging: causes, manifestations, and outcome". Journal of the National Medical Association. 87 (3): 220–4. PMC   2607819 . PMID   7731073.
  16. ↑ Lindner G, Funk GC (April 2013). "Hypernatremia in critically ill patients". Journal of Critical Care. 28 (2): 216.e11–20. doi:10.1016/j.jcrc.2012.05.001. PMID   22762930.
  17. ↑ Dehydration at eMedicine
  18. ↑ Bhave G, Neilson EG (August 2011). "Volume depletion versus dehydration: how understanding the difference can guide therapy". American Journal of Kidney Diseases. 58 (2): 302–9. doi:10.1053/j.ajkd.2011.02.395. PMC   4096820 . PMID   21705120.
  19. ↑ Thomas, James; Monaghan, Tanya (2014). Oxford Handbook of Clinical Examination and Practical Skills. Oxford University Press. ISBN   978-0-19-959397-2.
  20. ↑ Medicine, Institute of; Board, Food Nutrition (June 18, 2005). Dietary Reference Intakes: Water, Potassium, Sodium, Chloride, and Sulfate : Health and Medicine Division. ISBN   9780309091695 . Retrieved February 7, 2018.{{cite book}}: |website= ignored (help)
  21. ↑ Godman H (September 2016). "How much water should you drink?". Harvard Health. Retrieved February 7, 2018.
  22. ↑ Yamada, Yosuke; Zhang, Xueying; Henderson, Mary E. T.; Sagayama, Hiroyuki; Pontzer, Herman; Speakman, John R. (2022). "Variation in human water turnover associated with environmental and lifestyle factors". Science. 378 (6622): 909–915. Bibcode:2022Sci...378..909I. doi:10.1126/science.abm8668. PMC   9764345 . PMID   36423296.
  23. ↑ Noakes TD (2010). "Is drinking to thirst optimum?". Annals of Nutrition & Metabolism. 57 Suppl 2 (s2): 9–17. doi: 10.1159/000322697 . PMID   21346332.
  24. ↑ Taylor NA, Machado-Moreira CA (February 2013). "Regional variations in transepidermal water loss, eccrine sweat gland density, sweat secretion rates and electrolyte composition in resting and exercising humans". Extreme Physiology & Medicine. 2 (1): 4. doi: 10.1186/2046-7648-2-4 . PMC   3710196 . PMID   23849497.
  25. 1 2 Coyle EF (January 2004). "Fluid and fuel intake during exercise". Journal of Sports Sciences. 22 (1): 39–55. CiteSeerX   10.1.1.321.6991 . doi:10.1080/0264041031000140545. PMID   14971432. S2CID   14693195.
  26. ↑ Murray R, Stofan J (2001). "Ch. 8: Formulating carbohydrate-electrolyte drinks for optimal efficacy". In Maughan RJ, Murray R (eds.). Sports Drinks: Basic Science and Practical Aspects. CRC Press. pp. 197–224. ISBN   978-0-8493-7008-3.
  27. ↑ "Healthwise Handbook," Healthwise, Inc. 1999
  28. ↑ Wedro B. "Dehydration". MedicineNet. Retrieved June 10, 2014.
  29. ↑ "Can Humans drink seawater?". National Ocean Service. National Ocean Service NOAA Department of Commerce.
  30. ↑ "Find Water Article by Gary Benton - Simple Survival". www.simplesurvival.net.
  31. ↑ "At Home In The Wilderness Part II: Water". wildwoodsurvival.com.
  32. ↑ "EQUIPPED TO SURVIVE (tm) - A Survival Primer". www.equipped.com. Archived from the original on December 30, 2019. Retrieved October 26, 2013.
  33. ↑ "Five Basic Survival Skills in the Wilderness". Archived from the original on October 24, 2013. Retrieved October 26, 2013.
  34. ↑ Ellershaw JE, Sutcliffe JM, Saunders CM (April 1995). "Dehydration and the dying patient". Journal of Pain and Symptom Management. 10 (3): 192–7. doi: 10.1016/0885-3924(94)00123-3 . PMID   7629413.

Further reading

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.