How Hiccups Work

A cartoon image of a man drinking water trying to cure hiccups.
You might be able to stop a hiccup attack by holding your breath. Dorling Kindersley / Getty Images/Dorling Kindersley

We've all been tormented by hiccups at some point in our lives -- those annoying, involuntary fits that can make it nearly impossible to carry on a conversation, eat a meal or even maintain a train of thought. Most people hiccup four to 60 times per minute during a bout of hiccups, and everyone has a specific, lifelong hiccup pattern [source: eMedicine].

­­­The average hiccup spell can last from a few minutes to a few hours, but some people suffer from extended episodes that last days, months or even years. Hiccups that last longer than 48 hours are called persistent hiccups, and if they've lasted more than a month, you have intractable hiccups. Both types can cause serious health problems and, in some cases, even death.


For many of us, hiccups begin in the womb. The recapitulation theory proposes that fetuses use hiccups in respiration ­before their ­lungs are fully developed. This may help explain why premature infants spend up to 2.5 percent of their time hiccuping -- more than full-term babies [source: eMedicine].

­As we get older, bouts of hiccups decrease. The most likely time to hiccup is in the evening. Women can hiccup more during the first two weeks of their menstrual cycle, so pregnant women tend to hiccup far less than their nonpregnant counterparts do.

Why do we hiccup? The scientific community has been debating the issue for decades. Read on to learn what happens during a hiccup, the major hiccup theories, how hiccups start and how to stop them.



What Causes a Hiccup?

People have been pondering the precise cause of hiccups for thousands of years. Ancient Greek physician Galen, for example, hypothesized that hiccups were simply violent emotions that began in the stomach and erupted out the mouth. This hypothesis has not exactly been disproved, but since then, we have come up with many more.

We know what happens during a hiccup. During normal breathing, we take in air from the mouth and nose, and it flows through the pharynx, past the glottis and into the larynx and trachea, ending in the lungs. The diaphragm, a large muscle between the chest and abdomen, aids this airflow. It moves down when we inhale, and then up when we exhale. The phrenic nerves control the movement and sensation of the diaphragm. Any irritation to these nerves induces a spasm of the diaphragm. This spasm causes a person to take a short, quick breath that is then interrupted by the closing of the epiglottis (a flap that protects the glottis, the space between the vocal cords). The sudden closing creates the sound we all know as a hiccup.


So, hiccups are the result of diaphragm spasms. But what causes the irritation that leads to the spasm? There are only a few culprits for common hiccups, which usually disappear within a few minutes. One of the main irritants is a full stomach -- a result of swallowing too much food or air. A distended stomach pushes against the phrenic nerves of the diaphragm, increasing the possibility of irritation and, therefore, hiccups. A full stomach of spicy food can do double damage -- hot foods can be especially irritating to those nerves. As any smoker on a bender can tell you, excess smoking and drinking alcohol can also cause hiccups. A rapid temperature change outside or inside your stomach, from a cold night or a hot beverage, can be irritating enough to induce hiccups. Finally, emotions -- shock, excitement and stress -- can also trigger a hiccup fit.

Persistent and intractable hiccups can have more serious causes. There are hundreds, from hysteria to heart attacks, but most fit into one of five categories: central nervous system problems, metabolic problems, nerve irritation, anesthesia or surgery, and mental health issues. Because these causes are so varied and potentially serious, anyone suffering from hiccups for more than 48 hours should head straight to a doctor.



How to Stop Hiccups

Swallowing sugar could change nerve impulses in your tongue, perhaps stopping diaphragm spasms.
© Photographer: Milosluz | Agency: Dreamstime

Once you have hiccups, you'll probably want to get rid of them ASAP. And you'll probably be overloaded with treatment options from well-meaning onlookers -- anything from swallowing a spoonful of sugar to pulling on your tongue . But no one solution has been proven to be more effective than another -- it seems to depend on the person and the specific situation. And medical advice can be just as varied, with treatments ranging from a digital rectal exam to surgery.

Before you start slurping down peanut butter, though, hang on for a few minutes -- most cases of hiccups resolve on their own.


However, if you just can't wait, or if they just won't stop, a home remedy is worth a try. Some of the most popular home remedies work by stimulating the nasopharynx, the part of the pharynx behind the tonsils that is continuous with the nasal passage. These remedies -- drinking from the far side of the glass, biting into a lemon, or pulling on your tongue -- are often helpful in relieving hiccups that have lasted for a few minutes.

Other popular methods -- like holding your breath - can stop hiccups by interrupting the respiratory cycle. Breathing into a paper bag, quickly downing a glass of cold water and being startled also work for the same reason. No one is exactly sure why, but mental distraction often stops hiccups. To try it out, simply have someone put you on the spot and demand to see a hiccup. If these methods aren't effective, acupuncture and hypnosis have been successful for some persistent hiccup sufferers.

­Medical maneuvers are usually reserved for those with persistent or intractable hiccups. Tapping or rubbing the back of the neck, massaging the carotid sinus (an artery in the neck), and applying pressure to the eyeball can stimulate the nerves of the diaphragm. Diaphragm-relaxing medication is also an option for some patients. More invasive treatments include stimulation of the pharynx using a tube through the nose or mouth, a digital rectal massage that may stimulate the nerve controlling the glottis, emptying the stomach through a tube in the nose, and surgery to block the nerves to the diaphragm.

Check out the links on the next page for more information on hiccups and how to stop them.


Lots More Information

Related HowStuffWorks Articles

More Great Links


  • ­Mayo Clinic: Hiccups.
  • eMedicine: Hiccups.
  • WebMD: Hiccups.