Editing Urea (section)

===Medical use===
[[Urea-containing cream]]s are used as topical [[dermatology|dermatological]] products to promote [[Fluid replacement|rehydration]] of the [[skin]]. Urea 40% is indicated for [[psoriasis]], [[xerosis]], [[onychomycosis]], [[ichthyosis]], [[eczema]], [[keratosis]], [[keratoderma]], corns, and [[calluses]]. If covered by an [[occlusive dressing]], 40% urea preparations may also be used for nonsurgical [[debridement]] of [[nail (anatomy)|nails]]. Urea 40% "dissolves the intercellular matrix"<ref>{{cite web|url=http://www.odanlab.com/urisec/winter/|title=UriSec 40 How it Works|date=January 2009|publisher=Odan Laboratories|access-date=February 15, 2011|archive-date=2 February 2011|archive-url=https://web.archive.org/web/20110202150107/http://www.odanlab.com/urisec/winter/|url-status=dead}}</ref><ref name="Urea40">{{cite web |url=https://odanlab.com/product/urisec-40/ |title=UriSec 40% Cream |publisher=Odan Laboratories |access-date=August 20, 2021}}</ref> of the nail plate. Only diseased or dystrophic nails are removed, as there is no effect on healthy portions of the nail.<ref>{{Cite book |last=Habif |first=Thomas P. |url=https://books.google.com/books?id=kDWlWR5UbqQC&dq=Urea+removed+dystrophic+nails&pg=PA961 |title=Clinical Dermatology E-Book |date=2009-11-25 |publisher=Elsevier Health Sciences |isbn=978-0-323-08037-8 |language=en}}</ref> This drug (as [[carbamide peroxide]]) is also used as an earwax removal aid.<ref name="WebMD-eardrops">{{cite web |title=Carbamide Peroxide Drops GENERIC NAME(S): CARBAMIDE PEROXIDE |url=https://www.webmd.com/drugs/2/drug-3616/carbamide-peroxide-otic-ear/details |publisher=WebMD |access-date=August 19, 2021}}</ref>

Urea has also been studied as a [[diuretic]]. It was first used by Dr. W. Friedrich in 1892.<ref>{{cite journal | vauthors = Crawford JH, McIntosh JF | title = The use of urea as a diuretic in advanced heart failure | journal = [[JAMA Internal Medicine|Archives of Internal Medicine]] | volume = 36 | issue = 4 | pages = 530–541 | location = New York | date = 1925 | doi = 10.1001/archinte.1925.00120160088004 }}
</ref> In a 2010 study of ICU patients, urea was used to treat [[Euvolemia|euvolemic]] [[hyponatremia]] and was found safe, inexpensive, and simple.<ref>{{cite journal | vauthors = Decaux G, Andres C, Gankam Kengne F, Soupart A | title = Treatment of euvolemic hyponatremia in the intensive care unit by urea | journal = Critical Care | volume = 14 | issue = 5 | pages = R184 | date = 14 October 2010 | pmid = 20946646 | pmc = 3219290 | doi = 10.1186/cc9292 | doi-access = free }}</ref>

Like [[Saline (medicine)|saline]], urea has been injected into the [[uterus]] to induce [[abortion]], although [[Instillation abortion|this method]] is no longer in widespread use.<ref>{{cite journal | vauthors = Diggory PL | title = Induction of therapeutic abortion by intra-amniotic injection of urea | journal = British Medical Journal | volume = 1 | issue = 5739 | pages = 28–9 | date = January 1971 | pmid = 5539139 | pmc = 1794772 | doi = 10.1136/bmj.1.5739.28 }}</ref>

The [[blood urea nitrogen]] (BUN) test is a measure of the amount of nitrogen in the blood that comes from urea. It is used as a marker of [[renal function]], though it is inferior to other markers such as [[creatinine]] because blood urea levels are influenced by other factors such as diet, dehydration,<ref>{{cite journal | vauthors = Traynor J, Mactier R, Geddes CC, Fox JG | title = How to measure renal function in clinical practice | journal = BMJ | volume = 333 | issue = 7571 | pages = 733–7 | date = October 2006 | pmid = 17023465 | pmc = 1592388 | doi = 10.1136/bmj.38975.390370.7c }}</ref> and liver function.

Urea has also been studied as an excipient in drug-coated balloon (DCB) coating formulations to enhance local drug delivery to stenotic blood vessels.<ref>{{Cite journal|last1=Werk Michael|last2=Albrecht Thomas|last3=Meyer Dirk-Roelfs|last4=Ahmed Mohammed Nabil|last5=Behne Andrea|last6=Dietz Ulrich|last7=Eschenbach Götz|last8=Hartmann Holger|last9=Lange Christian|date=2012-12-01|title=Paclitaxel-Coated Balloons Reduce Restenosis After Femoro-Popliteal Angioplasty|journal=Circulation: Cardiovascular Interventions|volume=5|issue=6|pages=831–840|doi=10.1161/CIRCINTERVENTIONS.112.971630|pmid=23192918|doi-access=free}}</ref><ref>{{Cite journal|last=Wöhrle|first=Jochen|date=2012-10-01|title=Drug-Coated Balloons for Coronary and Peripheral Interventional Procedures|journal=Current Cardiology Reports|volume=14|issue=5|pages=635–641|doi=10.1007/s11886-012-0290-x|pmid=22825918|s2cid=8879713}}</ref> Urea, when used as an [[excipient]] in small doses (~3 μg/mm<sup>2</sup>) to coat DCB surface was found to form crystals that increase drug transfer without adverse toxic effects on vascular [[endothelial cells]].<ref>{{Cite journal|last1=Kolachalama|first1=Vijaya B.|last2=Shazly|first2=Tarek|last3=Vipul C. Chitalia|last4=Lyle|first4=Chimera|last5=Azar|first5=Dara A.|last6=Chang|first6=Gary H.|date=2019-05-02|title=Intrinsic coating morphology modulates acute drug transfer in drug-coated balloon therapy|journal=Scientific Reports|volume=9|issue=1|pages=6839|doi=10.1038/s41598-019-43095-9|pmid=31048704|pmc=6497887|bibcode=2019NatSR...9.6839C}}</ref>

Urea labeled with [[carbon-14]] or [[carbon-13]] is used in the [[urea breath test]], which is used to detect the presence of the bacterium ''[[Helicobacter pylori]]'' (''H. pylori'') in the [[stomach]] and [[duodenum]] of humans, associated with [[peptic ulcer]]s. The test detects the characteristic enzyme [[urease]], produced by ''H. pylori'', by a reaction that produces ammonia from urea. This increases the pH (reduces the acidity) of the stomach environment around the bacteria. Similar bacteria species to ''H. pylori'' can be identified by the same test in animals such as [[ape]]s, [[dog]]s, and [[cat]]s (including [[big cat]]s).