Why do we get hiccups?

It comes out of nowhere: that involuntary, repeated “hic” you can’t control and that, sometimes, just won’t stop. Hiccups are so common we barely pay attention to them, but behind them lies a small coordination glitch between a muscle and a valve in your throat. Here’s what happens and which tricks actually make sense.

What a hiccup really is

The star of the show is the diaphragm, the large dome-shaped muscle that separates the chest from the abdomen and that we use to breathe. A hiccup is an involuntary, sudden contraction of the diaphragm. As the Mayo Clinic explains, after each spasm the vocal cords snap shut, and that sudden closing of the glottis is what produces the characteristic “hic” sound.

In other words: the diaphragm jerks, air rushes in, and a valve cuts it off abruptly. Hence the noise.

Why it happens

Hiccups are usually triggered by things that irritate or stretch the diaphragm or the nerves that control it (the phrenic and vagus nerves). The most common causes, according to MedlinePlus, are everyday ones:

• Eating too much or too fast.
• Fizzy drinks or alcohol.
• Swallowing air (for example, chewing gum or talking while you eat).
• Sudden temperature changes.
• Strong emotions: laughter, nerves, stress, or excitement.

In these cases the hiccup is harmless and lasts only a few minutes.

Home tricks (and why some work)

There are a thousand folk remedies, and while none is foolproof, many share a common logic: raising the carbon dioxide in your blood or stimulating the vagus nerve to “reset” the diaphragm’s rhythm. The most reasonable are:

• Holding your breath for a few seconds.
• Breathing into a paper bag (never plastic).
• Sipping water in small sips or from an awkward position.
• Swallowing a teaspoon of sugar.
• Triggering a distraction or a little scare.

There’s no guarantee, but at least they have a physiological explanation behind them.

When hiccups stop being normal

The occasional hiccup worries no one. However, it’s worth seeing a doctor if the hiccups:

• Last more than 48 hours (persistent hiccups).
• Recur very frequently.
• Interfere with sleep, eating, or breathing.

In those rare cases they may be a sign of an underlying condition worth checking.

A little body short-circuit

A hiccup is, at heart, a brief mismatch in the coordination between the diaphragm and breathing: a fleeting, almost always harmless “short-circuit.” Knowing what triggers it helps you avoid it —eat calmly, without excess gas or air— and take those unannounced “hics” with humor. And if you try the paper-bag trick, now you know why it might work.