We’ve all had them. They come suddenly, they’re weird, and they’ll always overstay their welcome. We all know the various ways to get rid of them—drinking water, holding your breath, getting a fright—but all of them only work sometimes, and the phenomenon remains a mystery. For all the knowledge on how to cure this peculiar bodily function, most of us understand very little about what exactly causes them. What Happens When We Hiccup? So what exactly happens when we hiccup? The effect that we feel is simply a twitch of the diaphragm, but that’s only the end process. The mechanism is a reasonably complex motor act. During a hiccup, the diaphragm, the intercostal muscles (external, internal, and innermost, the Subcostalis, and the Transversus Thoracis), and the neck muscles all make a very sudden and dramatic contraction. Within a fraction of a second of this contraction beginning, the vocal cords (the …