The “Whys” of Baby Hiccups

It seems like no condition is both well-known and poorly understood as hiccups. Fortunately, singultus, as hiccups is officially known, is almost never a major issue in babies. Since almost all infants (and fetuses) will suffer from the condition at one time or another, though, it’s worth looking at what we know about them. Once we examine possible causes, it’s easier to understand the logic (or lack thereof) of treatments that have been recommended over the ages.

The Anatomy of It All

The actual hiccup is produced by contraction of the diaphragm, a muscle that separates the chest cavity (containing the lungs) and the abdominal cavity (containing the stomach, intestines, and multiple other organs). Contraction of the intercostal muscles between the ribs also occurs. Because the diaphragm and intercostal muscles aid in breathing, one theory is that hiccups, particularly those that develop before the baby is born, aid in lung development, or that it’s a remnant of a process that helps develop the ability to receive oxygen in other creatures, such as fish.

The hiccup process also involves nerves that run from the diaphragm to the brain and back down to the diaphragm. This type of arrangement is known as a reflex arc, like the one that’s involved when a doctor taps a knee with a rubber hammer.

When you look at the body’s “real estate” near these structures, it becomes a little clearer how problems in these areas might contribute to the development of hiccups. The lungs lie just above the diaphragm. The esophagus, (food tube), runs through the diaphragm to the stomach which lies immediately below. The nerves that run to and from the brain, of course, pass through the neck area, and a nerve going to the larynx (voice box) is involved in the hiccup reflex. The brain itself is, of course, involved in the reflex arc, and areas of the brain that control other functions in the body lie in close proximity to those that govern the hiccup process.

What Happens, and What Can Cause Hiccups

Hiccups, then, are a sort of “charley horse” of the diaphragm—a still poorly understood, involuntary contraction. Given the location, a variety of lung diseases (pneumonia, for example) and gastrointestinal (stomach and intestine) diseases can be the cause. So can issues with the ears, nose and throat. Drugs and nerve diseases can be culprits, as can infections. (Ebola virus, a  germ found in Africa, often has hiccups as one of its symptoms).

Many of these causes can be serious, and hiccups, especially if chronic, may need to be investigated. Fortunately, these more severe illnesses mostly affect adults and are extremely rare in babies, who are more likely to have short bouts with either a relatively benign cause or no discernible cause at all.

In order to pinpoint a common culprit in an infant, we look to the diaphragm’s neighbor, the stomach. Distention of the stomach with air can press on the diaphragm and its nerves, setting the process in motion. Another sometime cause is gastroesophageal reflux, a process where the feeding product (breast milk or formula) goes back up the esophagus (think: crossing the diaphragm). Even without reflux, a stomach full of milk can wield enough pressure upstairs to get things rolling.

Restoring the Peace

In weeding through the litany of treatment methods handed down over the centuries, it’s probably most important to declare one mantra: do no harm! Baby hiccups are generally a very benign process and do not hurt the little one. There are some “cures” you may have heard of that shouldn’t be used on anyone; others are OK for older people but not babies.

Not much has changed in the field of baby hiccup management since Dr. Rucoba’s blog last year (and read it here for more information), but it’s worth going over a few basic, benign changes that may prevent and/or treat hiccups. Even though feeding can cause hiccups, a small, slow drink can sometimes stop them. More frequent, smaller feedings may help, as may measures that will get the baby swallowing less air (for example, feeding more upright or, for formula fed babies, a change of bottle or nipple). Finally, if your baby is showing signs of gastroesophageal reflux, talk to your baby’s provider for advice.

It looks like hiccups is going to take a similar place in medical history to that of the common cold—a relatively harmless annoyance for which the chances of finding a true cure are slim. But like a cold, hiccups are over with quickly, and the older a child gets, the less of them there are!

Stan Sack
Dr. Stan Sack has 29 years’ experience as a primary care pediatrician in Massachusetts and Florida. A medical writer since 2015, he enjoys blogging on topics that are on parents’ minds but are covered less often in books and on websites. He lives in the Florida Keys with his family and enjoys healthy cooking, fitness activities and singing in his spare time.

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