Everyone has experienced hiccups at one point or another. Sometimes it happens when drinking a favorite carbonated beverage, or when you’re very hungry and eat lunch too quickly. It probably even happened before you were born, since it’s common for developing human fetuses to come down with a case of the hiccups while in the womb.
Superstition for why the hiccups occur are nearly as prevalent as their cure. In parts of Europe and Asia, hiccups are a sign that you’re popular. During medieval times, it was believed that hiccups were caused by elves. In Japan, one superstition holds that hiccupping 100 times in a row means that you’ll soon meet an untimely death.
One of the big reasons why hiccups are so mysterious? They’re difficult to study. It’s hard to induce hiccups in a test group, and much existing research is centered on subjects with problematic hiccups that have lasted anywhere from several days to several years. The world record for hiccups is held by Iowa farmer Charles Osborne, who had the hiccups for 68 years!
They seem to serve no useful purpose, so why do we hiccup? We explain the science behind these annoying spasms below, as well as some ways you might be able to cure them.
Why Do We Hiccup?
Humans use several different muscles to breathe, including the diaphragm, the neck muscles, and the intercostal muscles (which are located between the ribs). Hiccups are a sharp contraction of these muscles, which is then counteracted simultaneously by the inhibition of muscles that takes place during exhalation. At the same time, the back of the tongue and roof of the mouth move upward before the vocal cords clamp shut. This is what causes the “hic” sound that is synonymous with the hiccups.
These physiological responses lead scientists to believe that humans have a central pattern generator (CPG) somewhere in the brain. The neuronal circuit used to create hiccups is the same used for everyday responses such as breathing, sneezing and coughing. This conditional oscillator sends out an intermittent signal that results in a hiccup.
The Biological Evolution of Hiccups
Hiccups often occur when you swallow air. This typically takes place when eating or drinking too quickly, chewing gum or smoking cigarettes. Eating fatty foods or drinking carbonated or alcoholic beverages can also bring the hiccups on.
With no true purpose served by the hiccups, scientists have looked to amphibians for an answer. Humans and tadpoles both seem to experience similar electrical signals in the brain stem that are thought to trigger hiccups. Tadpoles also exhibit the same physiological behavior that causes hiccups in humans.
Halfway through development, tadpoles have both lungs and gills, enabling them to breathe both air and water. They fill their mouths with water, then use their vocal cords (also known as the glottis) to force this water out through the gills.
Some scientists believe that hiccups are a hangover from our evolutionary past, originating from our amphibian ancestors.
Cures for the Hiccups
For centuries, mankind has been coming up with cures for the hiccups. From sipping water on the wrong side of the glass to holding your breath, hiccup cures have long been steeped in superstition.
One cure? Singing a religious song. During the medieval times, people thought that hiccups were caused by elves. In fact, the Old English word for hiccup, ælfsogoða, literally translates into “elf hiccups.” In 10th century England, hiccup sufferers were instructed to prepare an herb salve, draw a cross, and sing a religious Latin verse. If you didn’t happen to know the language, you had to spit on your right forefinger, draw a cross on your left shoe, and recite the Lord’s Prayer – backwards.
If your Latin is rusty, you can try some other common hiccup cures:
- Breathe in and hold your breath for 10 seconds, then exhale slowly. Follow this breathing pattern three or four times, then repeat every 20 minutes as necessary.
- Hug your knees to your chest for two minutes.
- Gargle with iced water (or sip slowly on a glass of ice-cold water).
- Put gentle pressure on both sides of your nose while swallowing.
- Squirt a few drops of vinegar on your tongue.
Even if we don’t know exactly why humans get hiccups, at least we can understand part of the physiology behind this annoying response. And though hiccups are annoying, it’s better than being a tadpole!