Why do we burp? And the rare conditions that burps may reveal

Cookie shaped like a character with hand-drawn bubbles and sound waves to illustrate a belch

Admittedly, yours may not be the loudest burp ever (an accolade held by Australian Neville Sharpe, whose belch measured an amazing 112.4db – equivalent to the roar of a motorbike), but it would be embarrassing nevertheless. That said, if you happen to be dining in India, Turkey or China, your belch would be seen as ‘a compliment to the chef’, a definitive sign you’d enjoyed good food. But in other cultures it’s impolite, disrespectful and ruder even than slurping your soup!

In reality, this release of air happens to us all and is a natural process that your body uses to relieve a buildup of gas in the stomach. So, while a burp may sound and even smell repulsive it’s a necessary and common thing to happen, especially after eating, drinking and talking. Unfair then, that in polite company the only ones to get away with (and even be praised for) a hearty belch are babies, for whom a successful burp signals relief from stomach cramps and a chance that the rest of the household might get a good night’s sleep.

Why do we burp?

Burping is like a safety valve. Think of your stomach as a balloon: every time you swallow you take in air. If you eat too quickly, talk a lot while you eat, smoke or vape, use a drinking straw or chew gum, or have a blocked nose that forces you to breathe through your mouth, then you’ll be taking in more and more air and the walls of the balloon (your stomach) will be distending. At a certain point this becomes uncomfortable and the stomach will need to release some of this pressure.

Luckily for us, this is where the comparison to a balloon ends, as our stomach is unlikely to burst. Instead, receptors in the stomach wall alert our brain, which then signals a valve at the top of the stomach (called the lower oesophageal sphincter) to relax, allowing excess gas to escape back into the oesophagus or gullet. A second trigger releases a muscle (the upper oesophageal sphincter) at the throat, and this relaxes to release the burp (known as a gastric belch) through the mouth. This is an involuntary reflex, although some people can induce burping by taking in extra air.

A woman holding an illustration of the gut over her stomach

What causes us to burp?

As well as swallowing air, we get a buildup of gas from the digestive process, a byproduct of bacteria breaking down the food we’ve eaten. Certain foods are notorious for causing wind because they are harder to break down. Foods high in fibre, like lentils and beans, as well as cruciferous vegetables such as broccoli, are classic examples. For some, dairy may be a problem; these people are likely to be lactose intolerant, which means they lack the digestive enzyme (lactase) needed to break down lactose, the sugar naturally found in milk. Others may be sensitive to certain carbs, known as FODMAPs, which aren’t well absorbed by the body, get fermented by gut bacteria and – you guessed it – create gas.

Fizzy drinks, including sparkling water, will also increase burping. To create bubbles, manufacturers infuse small amounts of carbon dioxide into drinks. This means that when we drink a fizzy drink, we not only take in air when we swallow, but the gas from the bubbles also builds up in our stomach. And eventually there’s nothing for it but to burp it out.

How does burping differ from farting?

Of course, burping is not the only way the body releases gas. The other method, likely to cause more than a raised eyebrow and very likely an open window, is farting. Farts can also be caused by excess swallowed air, but the smelly, potent ones will have more to do with your gut microbes and the amount of fibre you’ve eaten.

Farts consist of gases like methane, nitrogen and carbon dioxide, with amounts varying (which is why the level of smell also varies!). Burps are mainly nitrogen and oxygen, although if you’ve downed a few sodas, there’ll be carbon dioxide in there as well, and possibly other gases connected with the foods you’ve eaten.

Read more about foods that make you fart.

Is my burping normal?

When it comes to how often we burp, some studies suggest a normal level can be as much as 30 times per day. It is only considered a problem when it becomes more frequent or distressing, particularly in social situations. That said, excessive burping can sometimes suggest an underlying health condition such as gastroesophageal reflux disease, acid reflux, gastritis (inflammation of the stomach lining) or an infection by a bacteria called Helicobacter pylori (H.pylori).

Your burps may well be odourless, but if they smell like rotten eggs, it’s likely there’s hydrogen sulphide among the gases you’re releasing. There can be a number of reasons for this. Foods like red meat, eggs, seafood, bananas or onions can be triggers. Or it could be a sign of an infection, either by the H.pylori bacteria or a parasite called Giardia.

Very frequent burping – in the region of 100-1000 times per day – which feels fast and furious, is known as supra-gastric belching. This differs from normal gastric belching because it involves the mouth, throat and gullet, and not the stomach. Done frequently it may induce conditions like acid reflux, heartburn and regurgitation. A supra-gastric belch is thought to be a self-induced, learned behaviour and not a reflex action.

Imagine if you couldn’t burp at all – this under-recognised condition leads to excess air in the stomach and gut, causing loud gurgling noises, bloating, discomfort and a lot of farting! ‘No-burp syndrome’ has only recently been defined and named (officially it’s called retrograde cricopharyngeal dysfunction, or R-CPD). It occurs when a muscle in the throat (the cricopharyngeal muscle – the main component of the upper oesophageal sphincter) is unable to relax to let a burp out. Successful treatment might involve the use of Botox injections to relax the muscle enough that it releases the trapped gases and that much longed-for belch.

Burp busters

Whether caused by your dietary choices or simply by swallowing too much air, burps serve their purpose. That said, if you’re looking to reduce how frequently you belch, follow these burp-busting tips:

Eat more slowly. Eating more mindfully may help reduce swallowed air and allow for a more efficient digestion.
Make an effort not to eat on the go, and stick to scheduled meal times.
Minimise the number of carbonated drinks you consume.
Limit burp-inducers like cucumber and green peppers.
Consider a stomach-calming cup of ginger tea to finish your meal.
Add a post-meal walk to help mobilise the intestines.
If you wear dentures, check they fit properly. Badly fitting dentures may cause you to swallow more air.
Avoid tight fitting clothing around your middle.

Why do we burp? And the reasons why we may burp too much or too little

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