Editing Dehydration (section)

== Signs and symptoms ==
[[File:PHIL 1939 lores.jpg|thumb|A person with severe dehydration due to [[cholera]], causing sunken eyes and wrinkled hands and skin]]
The hallmarks of dehydration include [[thirst]] and neurological changes such as [[headache]]s, [[Malaise|general discomfort]], loss of [[appetite]], [[nausea]], decreased [[urine]] volume (unless [[polyuria]] is the cause of dehydration), [[mental confusion|confusion]], unexplained [[Fatigue (medical)|tiredness]], purple fingernails, and [[Epileptic seizure|seizures]].<ref>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}}</ref> 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.<ref>{{cite journal | vauthors = Riebl SK, Davy BM | title = The Hydration Equation: Update on Water Balance and Cognitive Performance | journal = ACSM's Health & Fitness Journal | volume = 17 | issue = 6 | pages = 21–28 | date = November 2013 | pmid = 25346594 | pmc = 4207053 | doi = 10.1249/FIT.0b013e3182a9570f }}</ref> 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.<ref>{{cite journal |author-link=Harriet Hall | vauthors = Hall H |title=Are You Dehydrated? |journal=Skeptical Inquirer |date=August 17, 2020 | volume=4 |issue=4 |url=https://skepticalinquirer.org/exclusive/are-you-dehydrated/}}</ref> Many older people have symptoms of dehydration, with the most common being fatigue.<ref name="Hooper_2015">{{cite journal |vauthors=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 |date=April 2015 |title=Clinical symptoms, signs and tests for identification of impending and current water-loss dehydration in older people |journal=The Cochrane Database of Systematic Reviews |volume=2015 |issue=4 |pages=CD009647 |doi=10.1002/14651858.CD009647.pub2 |pmc=7097739 |pmid=25924806 |hdl-access=free |collaboration=Cochrane Kidney and Transplant Group |hdl=2066/110560}}</ref> Dehydration contributes to [[morbidity]] in the elderly population, especially during conditions that promote [[Transepidermal water loss|insensible]] free water losses, such as hot weather.