What causes hiccups - and how to stop them
Despite centuries of medical discoveries, our understanding of the humble hiccup has remained relatively foggy.
They can be caused by eating too much, drinking too much carbonation, hot chilis, alcohol, or smoking. But they can also be side effects of a range of medical conditions - and of some medical treatments.
There are three types of hiccups: acute, which last up to two days; persistent, which last up to a month; and intractable, which last even longer. The variety in causes means that for persistent and intractable hiccups, you're better off trying to isolate what might be triggering the hiccups and address that, rather than just finding a way to stop the hiccups.
And for acute hiccups, none of the hyped tactics like having someone scare you or holding your breath have actually been tested by scientists in a lab. But it's still worth running through some of them, since sometimes they do cut short an attack.
Other similar techniques with middling success include rebreathing in a paper bag, holding a cold compress to your face, and sniffing old-fashioned smelling salts. One scientist who led a review on hiccup treatment swears by holding your breath on the exhale.
But the bottom line is, as long as they go away in less than two days, hiccups may be annoying but they aren't worth worrying about.
Perhaps what's weirdest about hiccups is that no one can find any real reason for them in adults.
There is one theory that babies in the womb hiccup as practice for breathing to strengthen their muscles. But beyond that, science is stumped on this one.