Why Do We Get Hiccups and How to Stop Them?
Why do we get hiccups and how to stop them: the diaphragm reflex explained, which home cures actually work, and when persistent hiccups need a doctor.
Hiccups are absurd: a sudden, involuntary “hic” that arrives uninvited, refuses to leave, and has inspired a thousand folk cures — from being startled to drinking upside down. Beneath the comedy is a genuine neurological reflex involving the diaphragm, the vagus nerve and a hiccup “centre” in the brainstem. Most hiccups are harmless and brief. But why do we get them at all, which cures actually work, and when should hiccups worry you? Here is the science.
What a hiccup actually is
A hiccup is a two-part reflex. First, the diaphragm — the dome-shaped muscle under your lungs — and the muscles between your ribs contract suddenly and involuntarily, sucking air in. A fraction of a second later, your glottis (the opening between the vocal cords) snaps shut, cutting off the inflow. That abrupt closure is what makes the “hic” sound. The reflex arc runs through the vagus and phrenic nerves up to a hiccup centre in the medulla, near the brainstem’s breathing controls. In other words, hiccups are a glitch in the breathing machinery — a spasm of the exact muscles you use to inhale.
Why do we get them?
The honest answer: we are not entirely sure, especially about the evolutionary purpose. Leading theories suggest hiccups are a leftover from amphibian ancestors (tadpoles use a similar reflex to breathe through gills), or a mechanism that helped infant mammals coordinate suckling and breathing — which would explain why babies, including in the womb, hiccup so much. As for triggers in adults, the common ones all irritate the stomach, oesophagus or the nerves involved: eating too fast, overeating, fizzy drinks, sudden excitement or stress, alcohol, and acid reflux. Anything that distends the stomach or tickles the vagus nerve can set off the reflex arc.
Which cures actually work
Almost every folk cure aims at the same thing: raising carbon dioxide in the blood or stimulating the vagus nerve to reset the reflex. Holding your breath does both — CO₂ builds up and mild vagal stimulation occurs. Slow, deliberate breathing also calms the nervous system more broadly, which is why similar techniques appear in guides to sleeping better without tablets. The evidence base is thin (hiccup research is not lavishly funded), but physiologically plausible winners include: holding your breath as long as comfortable; breathing into a paper bag; sipping ice-cold water; bearing down as if for a bowel movement (the Valsalva manoeuvre); and pulling your knees to your chest and leaning forward. Being startled works only insofar as the gasp disrupts the breathing pattern — and deliberately frightening someone is a good way to lose a friend. What does not work: cures that do nothing to CO₂ or the vagus nerve, which is most of them. If one ritual works for you repeatedly, it is probably the breath-holding component doing the work.
When hiccups are not funny
Hiccups lasting more than 48 hours (persistent) or over a month (intractable) are a medical matter, not a comedy routine. They can signal nerve irritation or damage (from reflux, cysts, tumours or multiple sclerosis), metabolic problems (diabetes, kidney failure), or central nervous system issues (stroke, meningitis). Intractable hiccups can cause exhaustion, weight loss, depression and wound breakdown after surgery — they are genuinely debilitating. If hiccups persist beyond two days, recur frequently, or come with other symptoms, see your GP. Patient.info has a clear overview of persistent hiccup causes and treatments, and prescription options exist for the most stubborn cases. Prescription options exist, including baclofen, gabapentin and chlorpromazine, which calm the overactive reflex arc. The NHS hiccups guidance sets out when to seek help.
It is worth noting that persistent hiccups sometimes flag reflux or oesophageal irritation — the same territory as managing chronic irritation without heavy medication, where identifying the trigger matters more than suppressing the symptom.
The famous cases
The record for the longest hiccup attack belongs to Charles Osborne of Iowa, who hiccupped continuously from 1922 to 1990 — an estimated 430 million hiccups over 68 years. He lived a full life, married twice and fathered eight children, hiccupping through it all. His case, attributed to a burst blood vessel in the brain from a farming accident, reminds us that behind the joke reflex lies serious neurology.
Hiccups in babies and animals: why the young hiccup most
Babies hiccup constantly — in the womb, as newborns, through infancy — and it is completely normal. The leading explanation ties to the evolutionary theory: the hiccup reflex may help young mammals coordinate suckling, swallowing and breathing, expelling swallowed air from the stomach. Foetal hiccups, felt as rhythmic kicks in the third trimester, may be the developing nervous system practising breathing movements. They need no treatment and cause babies no distress, however alarming they sound to new parents.
Animals hiccup too, and the pattern supports the evolutionary story. Puppies and kittens hiccup frequently — any dog owner knows the adorable whole-body puppy hiccup after eating too fast. Horses, cows and even amphibians show hiccup-like reflexes; tadpoles rhythmically close their glottis while pumping water over their gills, in a pattern strikingly similar to human hiccups. This cross-species pattern is why biologists take the “gill-breathing leftover” theory seriously: the reflex is ancient, wired deep in the vertebrate brainstem, and we all inherited it. Your hiccups are, quite literally, a 300-million-year-old echo. And the simplest prevention of all: slow down at the table. Eating mindfully — chewing properly, pausing between bites — prevents the stomach distension that triggers most everyday hiccups. Your digestion will thank you too.
Conclusion
We get hiccups when the diaphragm spasms and the glottis snaps shut — a vagus-nerve reflex, probably an evolutionary leftover, triggered by stomach distension or nerve irritation. Breath-holding and vagal manoeuvres are the cures with real physiological logic. And if hiccups outstay 48 hours, they stop being funny and start being a symptom worth investigating.
Frequently Asked Questions
What causes hiccups?
A reflex arc: the diaphragm spasms involuntarily, then the glottis closes, making the “hic” sound. Triggers include eating too fast, fizzy drinks, overeating, excitement, alcohol and acid reflux.
What is the fastest way to stop hiccups?
Hold your breath as long as comfortable, or bear down (Valsalva manoeuvre). Both raise CO₂ and stimulate the vagus nerve, which can reset the reflex. Ice-cold water also helps many people.
Why do babies hiccup so much?
One theory is that hiccups helped infant mammals coordinate suckling and breathing — the reflex may be a developmental leftover that fades (but never fully disappears) with age.
When should I see a doctor about hiccups?
If they last more than 48 hours, keep recurring, or come with other symptoms. Persistent hiccups can indicate nerve, metabolic or neurological problems and there are effective prescription treatments.
Does being scared really cure hiccups?
Only incidentally — a startle causes a gasp that disrupts the breathing pattern. It is unreliable, and there are kinder ways to achieve the same reset.
Can hiccups be a sign of something serious?
Ordinary brief hiccups, no. But hiccups lasting over 48 hours can occasionally signal nerve irritation, reflux, or neurological issues — which is why persistent hiccups deserve a GP visit rather than home remedies.
Why do I always get hiccups when I drink fizzy drinks?
Carbonation expands the stomach rapidly, which can trigger the vagus-nerve reflex behind hiccups. Drinking slowly and letting some fizz settle first usually prevents it.
