It’s easy to dismiss hiccups as one of biology’s many irritating glitches—like goosebumps or the appendix.
They’re awkward, noisy, and inconvenient. But beneath the surface lies a fascinating mystery that researchers are still unraveling: why do we hiccup at all?
It turns out, hiccups might not be entirely pointless.
New studies suggest these spasmodic gulps could have an ancient purpose—one that stretches back hundreds of millions of years to a time when our ancestors lived underwater.
And they may still serve a crucial role in the early stages of life, especially for infants.
Let’s explore the science of hiccups, their strange evolutionary trail, and why your body still stubbornly clings to this prehistoric reflex.
The Reflex We Never Asked For
We all know the feeling: a strange tightening in your chest, a sudden hic, and then another—and another. Hiccups are defined as involuntary contractions of the diaphragm, the dome-shaped muscle just below your lungs.
These contractions are quickly followed by a rapid closure of your vocal cords, producing that characteristic “hic” sound.
But here’s what makes hiccups interesting: they often appear without warning, and for no obvious reason.
Unlike coughing, which helps clear your airways, or sneezing, which expels irritants, hiccups don’t seem to serve an immediate purpose—at least not in adults.
They’re rarely harmful, often embarrassing, and almost always inconvenient. Yet your body keeps doing it. Why?
This is where science begins to get fascinating.
Why Babies Hiccup So Much
Here’s something worth noting: infants hiccup a lot more than adults.
In fact, researchers estimate that babies can spend up to 2.5% of their time hiccuping—that’s around 15 minutes a day!
The leading theory? Hiccups may help newborn mammals expel excess air from their stomachs while feeding.
When infants suckle, they often swallow air along with milk. This air builds up in the stomach and can interfere with digestion or create discomfort.
Hiccups might function as a built-in burping reflex—a primitive way to help babies make room for more milk and stay comfortable.
It’s not just humans, either. Other mammals—dogs, cats, and even rodents—also hiccup in infancy, which suggests that this reflex is shared across species.
That kind of consistency points to something deeper, something old.
An Ancient Echo from Life Underwater
Let’s take a step back. Way, way back. To a time before humans existed, even before dinosaurs walked the Earth.
Enter: the tadpole.
As tadpoles prepare to transition from water-dwelling larvae to air-breathing adults, they face a complex respiratory challenge.
They need to direct water to their gills while preventing it from entering their developing lungs.
To do this, they perform a movement remarkably similar to a hiccup—a sudden, coordinated contraction of their throat and diaphragm muscles.
This reflex allows them to separate air from water—a life-saving adaptation during a critical stage of development.
And here’s the twist: this same reflex might have been inherited by our distant ancestors.
Long before mammals roamed the Earth, early vertebrates evolving in shallow seas and swamps may have developed this diaphragm spasm as part of their respiratory transition from water to land.
In this view, hiccups are an evolutionary relic—a leftover behavior from the time when creatures had to juggle lungs and gills.
As mammals evolved, the need for this skill faded. But the neural circuitry for the reflex? It stuck around.
Maybe Hiccups Aren’t Useless After All
Most of us have accepted that hiccups are pointless—a silly biological hiccup in the literal sense.
But this assumption might be wrong.
In 2023, a team of researchers at University College London proposed that hiccups might help “train” the brain to regulate breathing. I
n their study, they observed that hiccups in newborns caused large bursts of brain activity.
When a baby hiccupped, specific signals fired in their brainstem—the area responsible for controlling involuntary functions like breathing and heartbeat.
Their theory? These bursts of activity help newborns map the relationship between muscle contractions and the resulting sound.
It’s a form of sensorimotor learning—an internal bootcamp where the baby’s brain learns to monitor, control, and coordinate breathing patterns.
In other words, hiccups may help wire the brain for complex tasks like speaking, breathing rhythmically, and even swallowing properly.
It’s a developmental nudge toward mastering the art of being human.
This view flips the script. Rather than being a leftover glitch, hiccups might play a small but critical role in neurodevelopment—a stepping stone in a much bigger biological puzzle.
When Hiccups Become Dangerous
Most hiccups resolve on their own within a few minutes. But persistent hiccups—lasting over 48 hours—can be a sign of something serious.
Chronic hiccups have been linked to:
- Gastroesophageal reflux disease (GERD)
- Stroke or brain injury affecting the brainstem
- Multiple sclerosis
- Certain cancers
- Adverse drug reactions
President John F. Kennedy reportedly suffered from chronic hiccups due to a back injury that irritated his phrenic nerve.
And in 2007, Charles Osborne made history with the longest recorded case of hiccups: 68 years, from 1922 to 1990.
While extreme cases are rare, they highlight the strange power hiccups hold over the human body—a reflex that can become pathological when the balance of nerve signals goes awry.
Why Do We Still Hiccup as Adults?
If hiccups are mostly helpful for infants, why do we continue to hiccup as adults—long after we’ve stopped breastfeeding or growing neural networks?
Some researchers believe adult hiccups are just a byproduct of a deeply embedded reflex that the body never fully turned off.
Like a computer with outdated software still running in the background, your nervous system keeps the hiccup circuit on standby.
In adults, hiccups are often triggered by:
- Eating too quickly
- Drinking carbonated beverages
- Sudden changes in temperature
- Emotional stress or excitement
In each case, the diaphragm becomes irritated or stimulated, kicking off the involuntary spasm. The reflex doesn’t care whether it’s needed—it just acts.
This makes hiccups one of the few human behaviors that remain almost entirely beyond conscious control, even though they no longer serve a practical purpose for most of us.
Can You Cure a Hiccup?
Everyone has a favorite hiccup remedy. Hold your breath.
Drink a glass of water upside down. Scare the hiccups out. Breathe into a paper bag.
The reality? Most of these methods are based on anecdotal evidence.
But there are a few techniques that might work:
- Stimulating the vagus nerve – by drinking cold water, swallowing sugar, or pulling on your tongue.
- Interrupting the hiccup cycle – using controlled breathing or holding your breath.
- Resetting your diaphragm – by breathing into a bag to increase carbon dioxide levels and trigger a deeper breath.
Doctors may prescribe medications like baclofen, gabapentin, or chlorpromazine in extreme cases of chronic hiccups.
But for most people, hiccups remain harmless—and strangely persistent.
A Quirk of Evolution, A Gift to Infants, A Mystery to Science
So where does that leave us?
Hiccups are a physiological oddity—one part evolutionary leftover, one part developmental tool, and one part medical mystery.
They’re irritating but strangely consistent across mammals.
Pointless in adults, but potentially useful in newborns. A reflex from our watery past that still echoes in the modern human body.
In a world obsessed with efficiency and purpose, hiccups remind us that not every process in the body exists to serve our daily routines.
Some are whispers from history—remnants of a time when air and water danced together in lungs and gills, and survival meant adapting fast or dying out.
So the next time you get the hiccups, don’t just groan—listen. That little hic might be the voice of your ancestors calling from the depths of prehistory.
Liked this article? Share it with someone who always hiccups after soda. Or better yet—subscribe for more science stories like this one.
