Editing Water intoxication (section)

==Risk factors==
===Low body mass (infants)===
It can be very easy for children under one year old (especially those under nine months) to absorb too much water. Because of their small body mass, it is easy for them to take in a large amount of water relative to body mass and total body [[sodium]] stores.<ref>{{cite web|url=http://www.stlouischildrens.org/content/healthinfo/WaterIntoxicationinInfants.htm|title=Water Intoxication in Infants|access-date=31 August 2015}}</ref>

===Endurance sports===
[[Marathon]] [[running|runners]] are susceptible to water intoxication if they drink too much while running. This occurs when sodium levels drop below 135&nbsp;mmol/L, which can happen when athletes consume large amounts of fluid. This has been noted to be the result of the encouragement of excessive fluid replacement by various guidelines. This has largely been identified in marathon runners as a dilutional [[hyponatremia]].<ref name = "NEJMed1">{{cite journal  |vauthors=Almond CS, Shin AY, Fortescue EB, etal |title=Hyponatremia among runners in the Boston Marathon |journal=The New England Journal of Medicine |volume=352 |issue=15 |pages=1550–6 |date=April 2005  |pmid=15829535 |doi=10.1056/NEJMoa043901|s2cid=42909509 |doi-access=free }}</ref> A study conducted on runners completing the 2002 [[Boston Marathon]] found that thirteen percent finished the race with hyponatremia. The study concluded that the strongest predictor of hyponatremia was weight gain while racing (over-hydration), and hyponatremia was just as likely to occur in runners who chose sports drinks as those who chose water.<ref name = "NEJMed1"/>

===Military training===
Hyponatremia and other physical conditions associated with water intoxication are more often seen in those participating in military training. One US Army study found 17 trainees were admitted to a hospital over a year's period for water intoxication<ref>{{cite journal |last1=O'Brien |first1=K. K. |last2=Montain |first2=S. J. |last3=Corr |first3=W. P. |last4=Sawka |first4=M. N. |last5=Knapik |first5=J. J. |last6=Craig |first6=S. C. |title=Hyponatremia associated with overhydration in U.S. Army trainees |url=https://pubmed.ncbi.nlm.nih.gov/11370203/ |journal=Military Medicine |pages=405–410 |date=May 2001|volume=166 |issue=5 |doi=10.1093/milmed/166.5.405 |pmid=11370203 }}</ref> while another found that three soldiers had died, leading to a recommendation that no more than 1–1.5&nbsp;L of water should be consumed per hour of heavy sweating.<ref>{{cite journal |last1=Gardner |first1=John W. |title=Death by water intoxication |url=https://pubmed.ncbi.nlm.nih.gov/12053855/ |journal=Military Medicine |pages=432–434 |date=May 2002|volume=167 |issue=5 |doi=10.1093/milmed/167.5.432 |pmid=12053855 }}</ref>

===Overexertion and heat stress===
Any activity or situation that promotes heavy sweating can lead to water intoxication when water is consumed to replace lost fluids. Persons working in [[heat wave|extreme heat]] and/or humidity for long periods must take care to drink and eat in ways that help to maintain electrolyte balance. People using drugs such as [[MDMA]] (often referred to colloquially as "Ecstasy") may overexert themselves, perspire heavily, feel increased thirst, and then drink large amounts of water to rehydrate, leading to electrolyte imbalance and water intoxication – this is compounded by MDMA use increasing the levels of [[Vasopressin|antidiuretic hormone]] (ADH), decreasing the amount of water lost through urination.<ref>{{cite book |first=John |last=Timbrell |title=The Poison Paradox: Chemicals as Friends and Foes |url=https://books.google.com/books?id=qYYOtQU37jcC |year=2005 |publisher=OUP Oxford |isbn=978-0-19-280495-2}}</ref> Even people who are resting quietly in extreme heat or humidity may run the risk of water intoxication if they drink large amounts of water over short periods for rehydration.{{cn|date=November 2024}}

===Psychiatric conditions===
[[Psychogenic polydipsia]] is a psychiatric condition in which patients feel compelled to drink excessive quantities of water, thus putting them at risk of water intoxication. This condition can be especially dangerous if the patient also exhibits other psychiatric indications (as is often the case), as the caretakers might misinterpret the hyponatremic symptoms.<ref>{{Cite journal|last1=Zerbe|first1=Robert L.|last2=Robertson|first2=Gary L.|date=1981-12-24|title=A Comparison of Plasma Vasopressin Measurements with a Standard Indirect Test in the Differential Diagnosis of Polyuria|journal=New England Journal of Medicine|volume=305|issue=26|pages=1539–1546|doi=10.1056/NEJM198112243052601|issn=0028-4793|pmid=7311993}}</ref>

===Iatrogenic===
When an unconscious person is being fed intravenously (for example, [[total parenteral nutrition]]) or via a [[nasogastric tube]], the fluids given must be carefully balanced in composition to match fluids and electrolytes lost. These fluids are typically [[Tonicity#Hypertonic solution|hypertonic]], and so water is often co-administered. If the electrolytes are not monitored (even in an ambulatory patient), either [[hypernatremia]] or [[hyponatremia]] may result.<ref>{{cite journal |vauthors=Schwaderer AL, Schwartz GJ |title=Treating hypernatremic dehydration |journal=Pediatrics in Review |volume=26 |issue=4 |pages=148–50 |date=April 2005  |pmid=15805238 |doi=10.1542/pir.26-4-148}}</ref>

Some neurological/psychiatric medications ([[oxcarbazepine]], among others) have been found to cause hyponatremia in some patients.<ref>{{cite web|url=http://www.modern-psychiatry.com/oxcarbazepine.htm|title=Oxcarbazepine|access-date=31 August 2015|archive-date=23 October 2016|archive-url=https://web.archive.org/web/20161023080120/http://www.modern-psychiatry.com/oxcarbazepine.htm|url-status=dead}}</ref> Patients with [[diabetes insipidus]] are particularly vulnerable due to rapid fluid processing.<ref>{{Cite web|url=http://www.diabetesinsipidus.org/whatisdi.htm|title=What Is Diabetes Insipidus?|access-date=2011-12-02|archive-date=2010-07-29|archive-url=https://web.archive.org/web/20100729052008/http://www.diabetesinsipidus.org/whatisdi.htm|url-status=dead}}</ref>