{{short description|Release of gas from the upper digestive tract through the mouth}} {{redirect|Burp}} {{redirect|Belch|the fictional character|Sir Toby Belch}} {{Use dmy dates|date=December 2020}} {{Infobox medical condition (new) | name = Belch | image = Burp.wav | caption = | synonyms = Belching, ructus, eruptus, eructation | field = Gastroenterology | symptoms = | complications = | onset = | duration = | types = | causes = | risks = | diagnosis = | differential = | prevention = | treatment = | medication = | prognosis = | frequency = | deaths = }} '''Belching''' (also called '''burping''' and '''eructation''') is the audible release of gas from the upper gastrointestinal tract (esophagus and stomach) of humans, and other animals into the pharynx, and usually out through the mouth.<ref name="Stanghellini 2016"/>
In humans, belching can be caused by normal eating processes, or as a side effect of other medical conditions. When belching is excessive, it may be classed as a belching disorder, one of the gastroduodenal disorders.<ref name="Sun2015">{{cite journal |last1=Sun |first1=X |last2=Ke |first2=M |last3=Wang |first3=Z |title=Clinical features and pathophysiology of belching disorders. |journal=International Journal of Clinical and Experimental Medicine |date=2015 |volume=8 |issue=11 |pages=21906–14 |pmid=26885161 |pmc=4724007 }}</ref> Belching is a frequent symptom of gastroesophageal reflux disease (GERD) but this is distinct from a belching disorder.<ref name="Jeong2021">{{cite journal |last1=Jeong |first1=Shin Ok |last2=Lee |first2=Joon Seong |last3=Lee |first3=Tae Hee |last4=Hong |first4=Su Jin |last5=Cho |first5=Young Kyu |last6=Park |first6=Junseok |last7=Jeon |first7=Seong Ran |last8=Kim |first8=Hyun Gun |last9=Kim |first9=Jin-Oh |title=Characteristics of symptomatic belching in patients with belching disorder and patients who exhibit gastroesophageal reflux disease with belching |journal=Journal of Neurogastroenterology and Motility |date=30 April 2021 |volume=27 |issue=2 |pages=231–239 |doi=10.5056/jnm20114 |pmid=33424014 |pmc=8026376 }}</ref>
There is a range of levels of social acceptance for burping: within certain contexts and cultures, burping is acceptable. In some cultures and situations it may even be perceived as humorous, while in others it is seen as impolite or even offensive and therefore unacceptable. An infant often accumulates gas when feeding, and this needs to be vented by way of burping. To burp the baby is the common expression.<ref name="WebMD"/>
Belching is also very common among other mammals. In particular, burping by domesticated ruminants, such as cows or sheep, is a major contributor of methane emissions and may have a negative effect on the environment. Significant research is being done to find mitigation strategies for ruminant burping, such as by modifying the animals' diets with ''Asparagopsis taxiformis'', a type of red algae.<ref>{{Cite web|last=Fox|first=Alex|title=Seaweed-Fed Cows Burp Less Planet-Warming Methane|url=https://www.smithsonianmag.com/smart-news/seaweed-fed-cows-burp-less-planet-warming-methane-180977296/|access-date=2021-03-28|website=Smithsonian Magazine|language=en}}</ref>
==Causes== The '''belch reflex''' is responsible for the ability to belch. Most of the air that is swallowed during eating and drinking cannot be absorbed in the gastrointestinal tract and is vented by way of belching. Swallowed air is allowed to rise from the stomach into the esophagus, through a relaxed lower esophageal sphincter. The gaseous distention of the esophagus triggers the belch reflex in the relaxation and opening of the upper esophageal sphincter to release the air into the pharynx.<ref name="Kahrilas 2022"/>
The expelled gas is mainly a mixture of the main components of atmospheric air - oxygen and nitrogen.<ref>{{Citation|last=Cormier|first=René E.|title=Abdominal Gas|date=1990|url=https://www.ncbi.nlm.nih.gov/books/NBK417/|work=Clinical Methods: The History, Physical, and Laboratory Examinations|editor-last=Walker|editor-first=H. Kenneth|edition=3rd|publisher=Butterworths|isbn=0-409-90077-X|pmid=21250257|editor2-last=Hall|editor2-first=W. Dallas|editor3-last=Hurst|editor3-first=J. Willis}}</ref> Burps can be caused by drinking beverages such as beer and carbonated drinks, and in these cases, the expelled gas is mainly carbon dioxide.
Chewing gum, sucking on hard candy, talking while eating or drinking, or while smoking, can also cause more air to be swallowed and therefore increased belching. Also swallowing air may in some people be a nervous habit.<ref>{{Cite web |title=Practical tips to reduce bloating, belching and gas |url=https://www.mayoclinic.org/diseases-conditions/gas-and-gas-pains/in-depth/gas-and-gas-pains/art-20044739 |access-date=2024-08-14 |website=Mayo Clinic |language=en}}</ref>
Belching can also be a symptom of disorders that cause indigestion such as a hiatal hernia, gastritis, gastroesophageal reflux disease (GERD), an ulcer, infection with ''H. pylori'', gallbladder disease, and food allergies.<ref>{{cite web|url=http://wrongdiagnosis.com/symptoms/belching/book-causes-8c.htm|title=Eructation (Professional Guide to Signs & Symptoms (Fifth Edition)) - WrongDiagnosis.com|work=Better Medicine|access-date=4 October 2014|archive-url=https://archive.today/20120717175430/http://wrongdiagnosis.com/symptoms/belching/book-causes-8c.htm|archive-date=17 July 2012}}</ref><ref>{{Cite web|title=Belching: MedlinePlus Medical Encyclopedia|url=https://medlineplus.gov/ency/article/003080.htm|website=medlineplus.gov|language=en|access-date=2020-04-30}}</ref><ref>{{cite journal |last1=Hopman |first1=Wim P |last2=van Kouwen |first2=Mariëtte C |last3=Smout |first3=André J |title=Does (supra)gastric belching trigger recurrent hiccups? |journal=World Journal of Gastroenterology |date=14 April 2010 |volume=16 |issue=14 |pages=1795–1799 |doi=10.3748/wjg.v16.i14.1795 |pmid=20380015 |pmc=2852831 |doi-access=free }}</ref>
==Complications== In microgravity environments, burping is frequently associated with regurgitation, known as '''wet burping'''. With reduced gravity, the stomach contents are more likely to rise up into the esophagus when the gastroesophageal sphincter is relaxed, along with the expelled air.<ref>{{Cite web |first1=Vickie |last1=Kloeris |date=1 May 2001 |url=http://quest.arc.nasa.gov/people/journals/space/kloeris/05-01-01.html |title=Eating on the ISS |archive-url=https://web.archive.org/web/20060930025908/http://quest.arc.nasa.gov/people/journals/space/kloeris/05-01-01.html |archive-date=30 September 2006 |first2=Lori |last2=Keith |work=National Aeronautics and Space Administration |access-date=2011-11-12}}</ref>
==Clinical significance== thumb|upright=1.9|Diagrammatic flow chart for management of belching disorders
===Belching disorders=== Belching, when excessive, can be due to either of two '''belching disorders''', '''excessive supragastric belching''' or '''excessive gastric belching''', two types of gastroduodenal disorders.<ref name="Stanghellini 2016">{{cite journal |last1=Stanghellini |first1=V |last2=Chan |first2=FK |last3=Hasler |first3=WL |last4=Malagelada |first4=JR |last5=Suzuki |first5=H |last6=Tack |first6=J |last7=Talley |first7=NJ |title=Gastroduodenal Disorders. |journal=Gastroenterology |date=May 2016 |volume=150 |issue=6 |pages=1380–92 |doi=10.1053/j.gastro.2016.02.011 |pmid=27147122}}</ref> A belching disorder is also termed as a disorder of gut–brain interaction (DGBI).<ref name="Eypasch2025">{{cite journal |last1=Eypasch |first1=E |last2=Ebner |first2=M |last3=Leers |first3=J |title=The Unusual Patient in a Reflux Center: Belching, Rumination, Somatization as Pitfalls of Patient Selection for Anti-Reflux Surgery. |journal=Visceral Medicine |date=11 March 2025 |volume=41 |issue=3 |pages=159–165 |doi=10.1159/000545089 |pmid=40330637 |pmc=12052369 }}</ref>
Supragastric occurs above the stomach in the esophagus, and is classed as voluntary.<ref name="Moshiree2023">{{cite journal |last1=Moshiree |first1=Baha |last2=Drossman |first2=Douglas |last3=Shaukat |first3=Aasma |title=AGA Clinical Practice Update on Evaluation and Management of Belching, Abdominal Bloating, and Distention: Expert Review |url=https://www.gastrojournal.org/article/S0016-5085(23)00823-5/fulltext?referrer=https%3A%2F%2Fpubmed.ncbi.nlm.nih.gov%2F |journal=Gastroenterology |access-date=21 July 2025 |pages=791–800.e3 |language=English |doi=10.1053/j.gastro.2023.04.039 |date=1 September 2023 |volume=165 |issue=3 |pmid=37452811 |doi-access=free }}</ref> In supragastric belching the reflux episodes are mainly non-acidic making the use of proton pump inhibitors that reduce stomach acidity, non-effective.<ref name="Moshiree2023"/> This type of belching disorder is often linked to anxiety, and is classed as a behavioral disorder as is rumination syndrome, another gastroduodenal disorder.<ref name="Moshiree2023"/><ref name="Sawada2024">{{cite journal |last1=Sawada |first1=A |last2=Fujiwara |first2=Y |title=Belching Disorders and Rumination Syndrome: A Literature Review. |journal=Digestion |date=2024 |volume=105 |issue=1 |pages=18–25 |doi=10.1159/000534092 |pmid=37844547}}</ref>
Gastric belching arises from the stomach itself, and is classed as involuntary.<ref name="Moshiree2023"/> When gas is accumulated in the stomach it collects in the cardia the part nearest to the lower esophageal sphincter (LES). The increased volume stimulates stretch receptors in the wall of the stomach that initiates a vagovagal reflex that temporarily relaxes the LES, known as a ''transient LES relaxation/TLESR'', to allow air to move into the esophagus.
Both types of belching disorder may trigger reflux.<ref name="Sawada2024"/>
===Inability to belch syndrome=== A disorder that causes an inability to belch ('''abelchia''')<ref name="Oude Nijhuis 2021">{{cite journal | last1=Oude Nijhuis | first1=Renske A.B. | last2=Snelleman | first2=Jurjaan A. | last3=Oors | first3=Jac M. | last4=Kessing | first4=Boudewijn F. | last5=Heuveling | first5=Derrek A. | last6=Schuitenmaker | first6=Jeroen M. | last7=ten Cate | first7=Liesbeth | last8=Smout | first8=Andreas J.P.M. | last9=Bredenoord | first9=Albert J. | title=The inability to belch syndrome: A study using concurrent high-resolution manometry and impedance monitoring | journal=Neurogastroenterology & Motility | publisher=Wiley | volume=34 | issue=5 | date=2021-08-26 | article-number=e14250 | issn=1350-1925 | doi=10.1111/nmo.14250 | pmid=34435723 | pmc=9285907 | doi-access=free }}</ref> is known as retrograde cricopharyngeus dysfunction (R-CPD) or retrograde upper esophageal sphincter dysfunction (R-UESD), involves the cricopharyngeus muscle not being able to relax, leading to an inability to belch.<ref name="Kahrilas 2022">{{cite journal | last=Kahrilas | first=Peter J. | title=Retrograde upper esophageal sphincter function… and dysfunction | journal=Neurogastroenterology & Motility | publisher=Wiley | volume=34 | issue=5 | date=2022-02-04 | article-number=e14328 | issn=1350-1925 | doi=10.1111/nmo.14328 | pmid=35122356 | pmc=9007908 }}</ref><ref>{{Cite journal |last=Karagama |first=Yakubu |date=January 2021 |title=Abelchia: inability to belch/burp-a new disorder? Retrograde cricopharyngeal dysfunction (RCPD) |journal=European Archives of Oto-rhino-laryngology |volume=278 |issue=12 |pages=5087–5091 |doi=10.1007/s00405-021-06790-w |issn=1434-4726 |pmid=33893849 |doi-access=free|pmc=8553696 }}</ref> R-CPD was first discovered in 1987,<ref name="m566">{{cite web | title= Dysfunction of the belch reflex| url=https://www.gastrojournal.org/article/0016-5085(87)90445-8/pdf?referrer=https%3A%2F%2Fen.wikipedia.org%2F | access-date=2025-04-09}}</ref> and further research gained attention in the mid to late 2010s.<ref name="Bastian2019">{{cite journal |last1=Bastian |first1=Robert W. |last2=Smithson |first2=Melissa L. |title=Inability to Belch and Associated Symptoms Due to Retrograde Cricopharyngeus Dysfunction: Diagnosis and Treatment |journal=OTO Open |date=15 March 2019 |volume=3 |issue=1 |pages=2473974X1983455 |doi=10.1177/2473974X19834553 |pmid=31236539 |pmc=6572913 }}</ref> Common symptoms include stomach rumbling, bloating, and flatulence; lesser but common symptoms can be potentially painful hiccups, nausea, constipation, hypersalivation, or shortness of breath.<ref name="Bastian2019"/><ref name="Bastian 2021">{{cite web | last=Bastian | first=Dr. Robert | title=Can't Burp? Comprehensive Resources for R-CPD (in One Place) | website=Laryngopedia | date=2021-09-24 | url=https://laryngopedia.com/cant-burp-you-may-have-r-cpd-the-inability-to-burp/ | access-date=2022-08-24}}</ref> A high-resolution manometry, esophageal manometry or fluoroscopy by an ENT doctor is able to assess the issue.<ref name="Kahrilas 2022"/><ref name="Oude Nijhuis 2021"/> 80% of patients were successfully treated with botox after a single injection. If the injection is unsuccessful, an alternative is partial cricopharyngeal myotomy.<ref>{{cite journal |last1=Bastian |first1=Robert W. |last2=Hoesli |first2=Rebecca C. |title=Partial Cricopharyngeal Myotomy for Treatment of Retrograde Cricopharyngeal Dysfunction |journal=OTO Open |date=January 2020 |volume=4 |issue=2 |pages=2473974X2091764 |doi=10.1177/2473974X20917644 |pmid=32328538 |pmc=7163242 }}</ref> Chest pain associated with burping can rarely occur.<ref name="m566"/>
==Society and culture== ===Acceptance=== Some South Asian cultures view burping as acceptable in particular situations. For example, a burping guest can be a sign to the host that the meal satisfied them and they are full.<ref name="KYC">{{cite web| url = http://know.burrp.com/loose-ends/to-burrp-or-not-to-burrp/26173| title = To burp or not to burp| last = Mehrotra| first = Shirin| date = 10 October 2011| website = BURRP!| access-date = 2013-10-30| archive-url = https://web.archive.org/web/20131030104813/http://know.burrp.com/b-buzz/to-burrp-or-not-to-burrp/26173| archive-date = 2013-10-30}}{{deadlink|date=July 2025}}</ref>
In Japan, burping during a meal is considered bad manners.<ref>{{cite web |url=http://www.kwintessential.co.uk/cultural-services/articles/dining-etiquette-japan.html |title=Dining Etiquette in Japan | articles | cultural services |publisher=Kwintessential.co.uk |access-date=2014-01-22 |archive-url=https://web.archive.org/web/20131029193210/http://www.kwintessential.co.uk/cultural-services/articles/dining-etiquette-japan.html |archive-date=29 October 2013 }}{{deadlink|date=July 2025}}</ref> Burping during a meal is also considered unacceptable in Western cultures, such as North America and Europe.<ref name="KYC"/>
===Infants=== thumb|An infant being burped against an adult's shoulder Babies are likely to accumulate gas in the stomach while feeding and experience considerable discomfort (and agitation) until assisted. Burping an infant involves placing the child in a position conducive to gas expulsion (for example against the adult's shoulder, with the infant's stomach resting on the adult's chest) and then lightly patting the lower back. Because burping can cause vomiting, a "burp cloth" or "burp pad" is sometimes employed on the shoulder to protect clothing.<ref name="WebMD">{{cite web | url=http://www.webmd.com/parenting/baby/tc/burping-a-baby-topic-overview | title=Burping a Baby - Topic Overview | publisher=WebMD | date=18 February 2013 | access-date=16 April 2015}}</ref>
===World record=== The Guinness World Record for the loudest burp was 112.4 dB, set by Neville Sharp from Darwin, Australia in 2021.<ref>{{cite web |title=Loudest burp (male) |url=https://www.guinnessworldrecords.com/world-records/80129-loudest-burp-male |website=Guinness World Records |access-date=12 January 2024 |date=29 July 2021}}</ref> This is approximately as loud as a jet engine at {{convert|100|m|ft|abbr=on}}.<ref>{{Cite web|url=http://www1.lasalle.edu/~reese/decibels.htm|title=Decibel levels|website=www1.lasalle.edu|access-date=2018-11-02}}</ref> The record was previously held by Paul Hunn, who held the record for 12 years.<ref>{{cite web |last1=Suggitt |first1=Connie |title=Loudest burp record broken for first time in over a decade |url=https://www.guinnessworldrecords.com/news/2021/11/loudest-burp-record-broken-for-first-time-in-over-a-decade-683953 |website=Guinness World Records |access-date=13 January 2024}}</ref>
===Burped speech=== It is possible to voluntarily induce burping through swallowing air and then expelling it, and by manipulation of the vocal tract produce burped speech. While this is often employed as a means of entertainment or competition, it can also act as an alternative means of vocalisation for people who have undergone a laryngectomy, with the burp replacing laryngeal phonation. This is known as esophageal speech.<ref name="CRUK">{{cite web |title=Oesophageal speech after laryngectomy |url=https://www.cancerresearchuk.org/about-cancer/laryngeal-cancer/living-with/speaking-after-laryngectomy/oesophageal-speech |website=www.cancerresearchuk.org |access-date=29 July 2025 |language=en}}</ref>
==Other animals== Many other mammals, such as cows, dogs and sheep, also burp.
===Ruminants=== Much of the gas expelled is produced as a byproduct of the ruminant's digestive process. These gases notably include a large volume of methane, produced exclusively by a narrow cohort of methanogenic archaea in the animal's gut; ''Escherichia coli'' (''E. coli'') and other bacteria lack the enzymes and cofactors required for methane production. A lactating cow produces about 322g of methane per day,<ref>{{Cite journal|last1=Grainger|first1=C.|last2=Clarke|first2=T.|last3=McGinn|first3=S.M.|last4=Auldist|first4=M.J.|last5=Beauchemin|first5=K.A.|last6=Hannah|first6=M.C.|last7=Waghorn|first7=G.C.|last8=Clark|first8=H.|last9=Eckard|first9=R.J.|title=Methane Emissions from Dairy Cows Measured Using the Sulfur Hexafluoride (SF6) Tracer and Chamber Techniques|journal=Journal of Dairy Science|volume=90|issue=6|pages=2755–2766|doi=10.3168/jds.2006-697|pmid=17517715|year=2007|doi-access=free}}</ref> ''i.e.'' more than 117 kg per year through burping and exhalation, making commercially farmed cows a major (37%)<ref>{{Cite web|url=https://www.globalmethane.org/expo-docs/china07/postexpo/ag_gerber.pdf|title=Livestock's Long Shadow|last=Gerber|first=Pierre}}</ref> contributor to anthropogenic methane emissions, and hence to the greenhouse effect. 95% of this gas (wind) is emitted through burping.<ref>{{cite news|last1=Polakovic|first1=Gary|title=Bovine belching called udderly serious gas problem: Global warming concerns spur effort to cut methane|date=13 July 2003|url=http://www.mycattle.com/health/dsp_health_article.cfm?storyid=10045|archive-url=https://web.archive.org/web/20040813063303/http://www.mycattle.com/health/dsp_health_article.cfm?storyid=10045|archive-date=13 August 2004}}</ref> This has led scientists at the Commonwealth Scientific and Industrial Research Organisation of Perth, Australia, to develop an anti-methanogen vaccine to minimize methane in cow burps.<ref>{{cite news |author=Nowak, R. |title=Burp vaccine cuts greenhouse gas emissions |newspaper=New Scientist |date=5 September 2004 |url=https://www.newscientist.com/article.ns?id=dn6431}}</ref>
One reason why cows burp so much is that they are often fed foods that their digestive systems cannot fully process, such as corn and soy. Some farmers have reduced burping in their cows by feeding them alfalfa and flaxseed, which are closer to the grasses that they had eaten in the wild before they were domesticated.<ref>{{cite news |title=Greening the Herds: A New Diet to Cap Gas |newspaper=The New York Times|date=4 June 2009 |url=https://www.nytimes.com/2009/06/05/us/05cows.html}}</ref>
===Birds=== There is no documented evidence that birds burp, though ornithologists believe that there is nothing which physiologically prevents them from doing so. However, since the microbiota of birds do not include the same set of gas-producing bacteria that mammals have to aid in digestion, gas hardly builds up in the gastrointestinal tracts of birds.<ref name="Schwanke">{{cite web|last1=Schwanke|first1=Catherine|title=Is It True That Birds Can't Fart?|url=http://www.popsci.com/environment/article/2009-05/it-true-birds-cant-fart|website=Popular Science|access-date=18 June 2016|archive-url=https://web.archive.org/web/20160426034552/http://www.popsci.com/environment/article/2009-05/it-true-birds-cant-fart|archive-date=26 April 2016|date=4 June 2009}}</ref>
== See also == * Aerophagia * ''Penelope and the Humongous Burp''
==References== {{Reflist}}
== External links == {{Medical resources | ICD10 = {{ICD10|R|14||r|10}} | ICD9 = {{ICD9|787.3}} | DiseasesDB=30089 | MedlinePlus = 003080 }} {{Digestive system and abdomen symptoms and signs}}
Category:Reflexes Category:Symptoms and signs: Digestive system and abdomen