Regular viewers will be unsurprised to learn that the answer is ‘Nobody knows.’
A hiccup is a complex motor act, involving all the muscles used for breathing in making a sudden strong contraction. At the same time, the muscles used for breathing out are inhibited. The vocal cords clamp shut - that’s what makes the ‘hic’ sound. The diaphragm contracts, and the roof of the mouth and the back of the tongue move up. The heartbeat slows slightly. Researchers believe there is a neuronal circuit in the brain actually dedicated to producing hiccups, just as there are circuits for things like breathing and coughing. The odd thing is, hiccups have no apparent purpose, unlike coughing.
Essentially, during hiccups, we try as hard as possible to breathe in - while at the same time making sure it’s impossible to breathe in. Why on earth would we want to do that? It’s probably an evolutionary leftover. Hiccups are seen in a wide variety of other species, and are very common in human babies in the womb. Tadpoles at one stage in their development can breathe both air and water - they have both lungs and gills. They do something identical to hiccupping, to prevent them getting water in their lungs. So perhaps our hiccups are leftovers from an aquatic past.
One researcher reckons we’ve kept hiccupping because its circuitry also allows suckling, which we as mammals need. The actual hiccupping is no longer useful, but the circuitry that creates it is.
March 16th is National Hiccup Day.
The best cure for hiccups, in the sense that it’s medically proven, rather than being mere folklore, and involves no drugs or surgery - is digital rectal massage: a finger up the bottom. It’s been used successfully in cases of chronic hiccupping at least twice, in hospitals in Haifa, Israel, and in Tennessee.
Intractable hiccups are triggered by electrical impulses in the vagus nerve and the rectal massage addresses this by ‘overstimulating’ the vagus so as to disrupt those impulses. In Tennessee, the doctor tried various methods: gagging, tongue pulling, sinus massage and pressing the eyeball all failed, but Digital Rectal Massage did the trick. According to the Haifa medical team, an orgasm would work even better.
Through the centuries, many cures for hiccups have been suggested:
In Old English, hiccups were ælfsogoða - they were thought to be caused by elves; the QI Elves deny any involvement.
It’s said that if you hiccup more than seven times, you've got another 63 coming...
John Francis Crosland of North Carolina hiccupped for decades, and had a personalised number plate: HICUPMAN.
The accepted spelling today is hiccup. ‘Hiccough’ is considered an error in that it’s a back-formation that comes from a mistaken association with ‘cough’.
Earlier versions include hickop, hicket and hyckock - all, like hiccup, considered onomatopoeic in origin.
I think hiccup cures were really invented for the amusement of the patient's friends.
Babies in the womb often get hiccups which can be felt by the mother.
All mammals are known to get hiccups.