Why You Hiccup After Drinking Fizzy Pop?
From Bubbles to Bumps: What's Really Going On When You Hiccup After a Soda?
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In today's fun article, we check out why you might start to hiccup when you drink fizzy pop.
As with most of my articles, there is always a topical reason or something that happens in my life that is a good idea for one of my Five Whys. Today's article is no different. We were settling down with a cheeky fizzy drink while watching our TV programme when suddenly, a "hiccup" came next to me on the sofa. Now, I know what you are thinking - you'd expect a burp, as that's what's typically associated with fizzy drinks, but no, not this time. This time, it was a hiccup.
We laughed and joked about it and suggested she try some of the usual and not-so-usual ways to eliminate them. These included holding her breath, putting something wet on her forehead, and even visualising a green cow in a field. Nothing was working.
Eventually, they did go away, but they did carry into bed, and it got me thinking about why the fizzy pop had this effect. Let's have a fun journey to see if we can find out why in this edition of the Five Whys.
Why #1: Why do we hiccup when we consume fizzy juice?
Any carbonated liquid, whether fizzy juice or sparkling water, contains carbon dioxide (CO2). Once the gas hits your mouth and warms up, the CO2 starts to form bubbles. While some of this will come from burping, some gas enters your stomach. Although fizzy juice, in particular, is acidic and contains artificial sweeteners that might affect gut mobility, the stomach distension, or stretching, created from the gas is a primary trigger for hiccups.
Why #2: Why does the buildup of gas in the stomach lead to hiccups?
It might sound obvious that gas in the stomach would trigger hiccups, but what is the trigger? The stomach wall has special nerve endings known as stretch receptors. These detect when the stomach stretches and send signals to the medulla oblongata. The medulla oblongata is the lowest part of the brainstem and plays a role in autonomous functions such as breathing, heart rate and blood pressure. It is also responsible for reflex actions like hiccups. The hiccups then cause the diaphragm to spasm to expel the gas.
Why #3: Why does the diaphragm spasm during this process?
The reflex arc is the neural pathway that controls the reflex action; the vagus nerve is the messenger to signal the start of the reflex, but the phrenic nerve is activated to start the diaphragm contraction. This activation can be sudden and forceful, which explains why our bodies jolt during hiccups. Simultaneously, the opening between the vocal cords and the glottis rushes open. The contraction and opening of the glottis increases pressure in the chest cavity, creating the "hic" sound.
Why #4: Why does the vagus nerve play a part in hiccups?
As briefly mentioned, the vagus nerve is the messenger in the process. It is one of the longest cranium nerves in the body, connecting the brain to many vital organs, including the heart, lungs and digestive system. The vagus nerve is how the signals reach the brainstem to know that it has expanded from the gas. The acidity of the fizzy drinks can also irritate the vagus nerve, making it prone to triggering hiccups. The clever thing is that because it's a two-way communication network, the vagus nerve also plays a part in stopping hiccups. It can activate the parasympathetic system, help relax the diaphragm, and regulate breathing. This explains why some remedies such as controlled breathing, drinking water or holding your breath help.
Why #5: Why do our bodies develop the hiccup reflex when our stomachs get irritated?
It isn't fully known why the hiccup reflex is activated; certainly, fizzy juice wasn't around in the early days of our human ancestors. It is widely accepted, though, that hiccups are a reflex we've held onto since infancy. Newborns hiccup a lot, and it is believed this is a way to help clear amniotic fluid from the lungs after birth. As our bodies develop, we primarily expel air from the stomach through burping, which may help prevent the stomach from becoming damaged. Whilst speculative, hiccups might not be the most effective way to get rid of gas from our stomach and may even be a remnant of an evolutionary past that is no longer required.
In Summary...
Hiccups are likely triggered by irritation caused by the gas expanding the stomach and possibly the acidity activating the vagus nerve. The vagus nerve sends signals to the brainstem, where the reflex arc is activated. Once activated, signals are sent to the diaphragm to begin the involuntary spasm to expel the gas. At the same time, pressure is created in the chest cavity as the glottis opens. Once released due to the combination of the spasm, the sound of a "hic" is created. The vagus nerve plays a vital role as it receives signals and can activate the parasympathetic system to relax the muscles in the stomach and regulate breathing to stop the hiccups.
You might be wondering, what stopped my partner's hiccups the other day? She activated that parasympathetic system by practising deep breathing, and we all eventually got a good night's sleep.
Thank you for reading. Stay curious. Please like, subscribe, and comment to stay updated on my latest articles.
Matt