Editing Kidney failure (section)

== Classification ==
{{See also|Hepatorenal syndrome}}

Kidney failure can be divided into two categories: [[acute kidney failure]] or [[chronic kidney failure]]. The type of renal failure is differentiated by the trend in the serum [[Creatinine#Diagnostic use|creatinine]]; other factors that may help differentiate acute kidney failure from chronic kidney failure include [[anemia]] and the kidney size on [[sonography]] as chronic kidney disease generally leads to anemia and small kidney size.<ref>niddk.nih.gov, [Anemia in Chronic Kidney Disease](https://www.niddk.nih.gov/health-information/kidney-disease/anemia)</ref>

=== Acute kidney failure ===
{{Main|Acute kidney injury}}

[[Acute kidney injury]] (AKI), previously called acute renal failure (ARF),<ref>{{cite journal | vauthors = Moore EM, Bellomo R, Nichol AD | title = The meaning of acute kidney injury and its relevance to intensive care and anaesthesia | journal = Anaesthesia and Intensive Care | volume = 40 | issue = 6 | pages = 929–48 | date = November 2012 | pmid = 23194202 | doi = 10.1177/0310057X1204000604 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Ricci Z, Ronco C | title = New insights in acute kidney failure in the critically ill | journal = [[Swiss Medical Weekly]] | volume = 142 | pages = w13662 | year = 2012 | pmid = 22923149 | doi = 10.4414/smw.2012.13662 | doi-access = free }}</ref> is a rapidly progressive loss of [[renal function]],<ref name="Adam">{{cite encyclopedia |url=https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001530/ | archive-url = https://web.archive.org/web/20140117220151/https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001530/ | archive-date = 17 January 2014 |title=Acute kidney failure | encyclopedia = A.D.A.M. Medical Encyclopedia |year=2012 |publisher=U.S. National Library of Medicine |access-date=1 January 2013}}</ref> generally characterized by [[oliguria]] (decreased [[urine]] production, quantified as less than 400&nbsp;[[millilitres|mL]] per day in adults,<ref>{{cite journal | vauthors = Klahr S, Miller SB | title = Acute oliguria | journal = The New England Journal of Medicine | volume = 338 | issue = 10 | pages = 671–5 | date = March 1998 | pmid = 9486997 | doi = 10.1056/NEJM199803053381007 }}</ref> less than 0.5 mL/kg/h in children or less than 1 mL/kg/h in infants); and [[Water-electrolyte imbalance|fluid and electrolyte imbalance]]. AKI can result from a variety of causes, generally classified as ''prerenal'', ''intrinsic'', and ''postrenal''. Many people diagnosed with [[paraquat|paraquat intoxication]]  experience AKI, sometimes requiring [[hemodialysis]].<ref>Predictors of acute kidney injury after paraquat intoxication, [National Library of Medicine - National Institutes of Health](https://pmc.ncbi.nlm.nih.gov/articles/PMC5584253/)</ref>  The underlying cause must be identified and treated to arrest the progress, and [[Kidney dialysis|dialysis]] may be necessary to bridge the time gap required for treating these fundamental causes.{{citation needed|date=April 2023}}

===Chronic kidney failure===
{{Main|Chronic kidney disease}}
[[File:CKD - Chronic kidney disease.jpg|thumb|Illustration of a kidney from a person with chronic renal failure]]

[[Chronic kidney disease]] (CKD) can also develop slowly and, initially, show few symptoms.<ref>{{cite encyclopedia |url=https://www.nlm.nih.gov/medlineplus/ency/article/000471.htm |title=Chronic kidney disease |year=2011 |encyclopedia=A.D.A.M. Medical Encyclopedia |publisher=  Medline Plus, National Institutes of Health |access-date=1 January 2013}}</ref> CKD can be the long term consequence of irreversible acute disease or part of a disease progression.{{citation needed|date=August 2022}} CKD is divided into 5 different stages (1–5) according to the estimated glomerular filtration rate (eGFR). In CKD1 eGFR is normal and in CKD5 eGFR has decreased to less than 15&nbsp;ml/min.<ref>{{Cite web |date=2021-11-22 |title=Stages of kidney disease |url=https://www.kidneyfund.org/all-about-kidneys/stages-kidney-disease |access-date=2023-03-09 |website=www.kidneyfund.org |language=en}}</ref>

=== Acute-on-chronic kidney failure ===
Acute kidney injuries can be present on top of chronic kidney disease, a condition called acute-on-chronic kidney failure (AoCRF). The acute part of AoCRF may be reversible, and the goal of treatment, as with AKI, is to return the person to baseline kidney function, typically measured by serum [[creatinine]]. Like AKI, AoCRF can be difficult to distinguish from chronic kidney disease if the person has not been monitored by a [[physician]] and no baseline (i.e., past) blood work is available for comparison.{{citation needed|date=August 2022}}