In humans, burping can be caused by normal eating processes, or as a side effect of other medical conditions. There is a range of levels of social acceptance for burping: within certain context and cultures, burping is acceptable, while in others it is offensive or unacceptable.
Humans are not the only animals that burp: it is 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, i.e. modifying the animals' diets with Asparagopsis taxiformis (red
seaweed).[1]
Causes
Burping is usually caused by
swallowing air when eating or drinking and subsequently expelling it, in which case the expelled gas is mainly a mixture of
nitrogen and
oxygen.[2]
Burps can be caused by drinking beverages containing
carbon dioxide, such as
beer and
soft drinks, in which case the expelled gas is mainly carbon dioxide.
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.[8]
Disorders
Chest pain associated with burping can occur, but is rare.[9]
Retrograde cricopharyngeal dysfunction (R-CPD) or retrograde upper esophageal sphincter dysfunction (R-UESD),[10][11] also called "abelchia",[12] involves the
cricopharyngeus muscle not being able to relax, leading to inability to burp. R-CPD was first discovered in 2015.[13] Common symptoms include gurgling noises, bloating, and flatulence; lesser but common symptoms can be potentially painful hiccups, nausea, constipation, hypersalivation, or shortness of breath.[14][15] A
high-resolution manometry,
esophageal manometry or
fluoroscopy by an
ENT doctor is able to assess the issue.[11][10] 80% of patients were successfully treated with
botox after a single injection. If the injection is unsuccessful, an alternative is partial
cricopharyngeal myotomy.[16]
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.[17]
In
Japan, burping during a meal is considered bad manners.[18] Burping during a meal is also considered unacceptable in Western cultures, such as
North America and
Europe.[17] In
Middle Eastern countries, it is not acceptable to burp out loud in public, and one should silence one's burp, or at least attempt to do so.[citation needed]
Despite virtually no scientific research on the subject, small online communities exist for burping as a
sexual fetish.[19] Online, people of any
sexual orientation anecdotally report some attraction to burping, with what appears to be psychological and/or behavioural overlaps with other sexual fetishes including
body inflation,
feedism,
vorarephilia, and
farting fetishes.[20] Anecdotally, the 'loudness' aspect appears to be an important element to burp fetishists. Despite being a rather uncommon fetish,[21] it continues to follow a general well-known pattern of sexual behaviour where hearing influences sexual arousal and response, noting that "it is the noise made rather than the action itself that appears to be what is sexualized and/or interpreted by the fetishist as sexually pleasurable and arousing".[20]
Infants
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.[22]
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.
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.[30]
The failure to burp successfully can be
fatal. This is particularly common among domesticated
ruminants that are allowed to gorge themselves on spring
clover or
alfalfa. The condition, known as
ruminal tympany, is a high-pressure buildup of gas in the stomach(s) and requires immediate treatment to expel the gas, usually the insertion of a flexible rubber hose down the esophagus, or in extreme cases the lancing of the animal's side with a
trochar and cannula.[citation needed]
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.[31]
^Cormier, René E. (1990), Walker, H. Kenneth; Hall, W. Dallas; Hurst, J. Willis (eds.),
"Abdominal Gas", Clinical Methods: The History, Physical, and Laboratory Examinations (3rd ed.), Butterworths,
ISBN040990077X,
PMID21250257