nOne of the most common questions I get in the newborn nursery, especially from first time parents, involves hiccups. Babies hiccup in the womb and most, if not all of them, will have periodic bouts of hiccups in the neonatal period. But many new parents are surprised by their baby’s first spasmodic contractions of the diaphragm. When brought up, it is often to simply acknowledge that their baby had a run of a few hiccups, usually associated with a feed, with some parents expressing surprise and others nervousness. Regardless of their assumed motivation, I always provide reassurance that hiccups are a normal experience for babies, as they are across the entire spectrum of age.
The medical term for hiccups, which I admit I only learned while researching this topic, is “singultus.” We doctors like to use our own peculiar language as much as possible in order to maintain a sense of superiority when dealing with today’s internet savvy customers, I mean patients, and their families. The rumbling of your stomach, that’s actually borborygmus. You don’t have a unibrow above your nose, that’s a synophrys. It isn’t abdominal or pelvic discomfort associated with ovulation that keeps annoying you midway through your menstrual cycle, it’s mittelschmerz. But since this is a forum meant for general public consumption, I’ll use the rather pedestrian and philistine “hiccup” for the duration of the post.
What are hiccups and who gets them?
Simply put, a hiccup is the sudden occurrence of a spasm involving the diaphragm, usually the left half of it, and the intercostal (between the ribs) muscles, that occurs without warning. The muscular contraction causes a hard inspiration of air followed quickly by an involuntary closing of the vocal folds. This produces the “hic” that we all know and love. In the individual, the frequency of hiccups during any one bout are fairly consistent, ranging from a couple per minute to one per second, with a lot of variability episode to episode.
In the vast majority of cases, hiccups are classified as a bout. This means that they may last for less than a couple of days, but usually persist for only a few minutes. Longer episodes that last less than a month are defined as persistent, and are very rare. People with intractable hiccups, whose cases occasionally make the news (not always just for the hiccups!), have them for longer than one month. Intractable hiccups are exceedingly rare, but can result is significant problems for the sufferer depending primarily on how frequently they occur. Very frequent hiccups can interfere with eating and social functioning, for example.
There have been very few studies looking into hiccups, particularly the fairly rare intractable presentations, and no adequate controlled trials. The largest I could find involved 4 patients. We don’t know with certainty if there are any particular predilections, such as ethnicity or socioeconomic background, but a few small studies have found links between intractable hiccups and older age, gastric reflux associated inflammation of the esophagus and a variety of other chronic conditions. They also seem to occur a bit more frequently in men. The fact that the hiccup is such a largely misunderstood onomatopoeia, despite what you may read online or hear from your neighbor/chiropractor, naturally allows for them to be a frequent target of practitioners of all manner of so-called alternative medical practices as well as myriad culturally diverse home remedies.
What causes hiccups?
We don’t know for certain what hiccups are all about, which is not to say that we are flying completely blind. We may not know what provokes most individual bouts, but we have a general idea of precipitating factors and hiccups can even be reliably initiated in some people. We don’t know if hiccups serve some kind of beneficial purpose in mammalian development, or are a holdover from amphibian gill ventilation, not that there even has to be a reason for them at all. Not everything has to have a purpose or survival advantage. It is certainly very interesting that the hiccup only occurs in mammals, and in fact is found universally in them. But we do at least have the neural pathway mapped out…sort of.
Hiccups, we are fairly certain, occur via a reflex arc of neural activity. A signal comes into the brainstem, perhaps also targeting the nucleus of the phrenic nerve in the cervical spine and the hypothalamus, a vital forebrain structure found in all vertebrates, via the phrenic and vagus nerves, and maybe the sympathetic chain. The medulla oblongata and reticular formation of the brainstem, and again maybe the hypothalamus and phrenic nucleus, interact in some way, perhaps a miracle occurs, and a signal is sent back out via the phrenic nerve and other connections to the throat, diaphragm and chest wall. Hiccup.
We think that most bouts of hiccups are related to gastric and esophageal distention from a variety of causes, such as eating a bit too much or from drinking carbonated beverages. Hiccups can be induced with intentional dilation of the esophagus in many people, for instance, and many folks at least think that they get them every time they engage in a particular activity such as drinking or eating at the all you can eat buffet. Of course this could easily be attributable to confirmation bias. There are also associations with alcohol and changes in gastric temperature, as well as emotional stress. For the most part these are all just assumptions based on limited data and some animal studies.
The causes of persistent and intractable hiccups are a bit better understood, although not without a fair amount of assumptions as well. Vascular, infectious and structural diseases of the CNS have all been linked to severe episodes of hiccups, likely because of interference with the above mentioned neural pathways. Direct irritation of the vagus and phrenic nerve, such as from an inflammatory process or tumor, is believe to be a common culprit, as are gastrointestinal disorders that lead to distention and irritation of the stomach and esophagus. There are many more proposed causes, like reactions to a variety of drugs and even inflammation of the heart, but again most of them can only be considered to be associated with persistent or intractable hiccups. Evidence for a true causal relationship is lacking for pretty much everything, and in most cases no hidden cause is discovered.
Psychogenic factors probably play a large role in many cases of intractable hiccups, although this should always be considered a diagnosis of exclusion. This shouldn’t come as much of a surprise though. If stress and anxiety can result in psychogenic non-epileptic seizures, a foe I’ve battled many times as a pediatric hospitalist, they can certainly cause hiccups that aren’t related to any activation of the reflex arc. As with psychogenic seizures, psychogenic hiccups may emerge as an inappropriate coping strategy or as a means of achieving primary or secondary gain. And some patients, I have no doubt, are just plain faking them although I bet that malingering is considerably less common.
Is there a science-based approach to hiccups?
Just because we don’t fully understand everything about hiccups yet doesn’t mean that it’s the Wild West when it comes to evaluation and management. Well, it’s a bit like the Wild West. But if anything, simply recognizing that we don’t have all the answers separates us from the practitioners of irregular medicine. In most cases, which are usually brief and uneventful, people do not seek out medical care but many do attempt a variety of home remedies which I’ll get to in a bit. Persistent hiccups, and the rare intractable case, do deserve a thoughtful medical evaluation because of the possible link to underlying medical conditions, and there are treatments that might help.
A thorough history taking and physical exam is vital to the evaluation of persistent and intractable hiccups, and it is often all that is needed. Questions naturally should target the many possible underlying causes. One simple question that can potentially help immensely is whether or not the hiccups occur during sleep. It would be unlikely for purely psychogenic hiccups to occur while a patient is asleep.
If the history and physical are unhelpful, there are baseline labs that are recommended. These include tests of electrolyte levels, liver and kidney function and blood counts. Depending on any clues discovered, imaging may be warranted to look for disease in the head or chest. Direct visualization via endoscopy or bronchoscopy may even be needed to rule out disease in the GI and respiratory tracts respectively.
Time is by far the most successful and low-risk treatment for hiccups because, with some very notable exceptions, they are self-limited. Everything else, whether a home remedy or a conventional medical intervention, is largely based on anecdotes and other weak forms of evidence like case reports and the occasional case series. There are no legitimate RCTs and a 2013 Cochrane review, for what it’s worth, concluded that “There is insufficient evidence to guide the treatment of persistent or intractable hiccups with either pharmacological or non-pharmacological interventions.”
In general, if evaluation reveals a possible cause of the patient’s persistent or intractable hiccups, such as a tumor in the chest irritating the recurrent laryngeal nerve, treatment targeting the possible cause would seem prudent. But that is rarely the case. Because as physicians we must weight both the risks AND the benefits of a treatment plan, most would agree that a cautious initial approach to hiccups is best because even intractable cases tend to be more of an extreme annoyance than a dangerous medical problem. That being said, more severe and bothersome presentations might justify a more aggressive plan.
Physical maneuvers are usually tried first. These involve attempts to, at least theoretically, interrupt the reflex arc. Breath holding, drinking cold water, applying pressure to the diaphragm and bearing down against a closed airway to increase activity of the vagal nerve are common recommendations. Stranger physical maneuvers have been looked at, most infamously the use of digital rectal massage (1,2). The authors of these two papers shared a 2006 Ig Nobel Prize in Medicine for their effort.
The use of medications to treat persistent and intractable hiccups is usually tried only after physical maneuvers fail and a careful assessment of the risks and benefits. Pharmaceutical interventions do not have supporting evidence any more robust than physical maneuvers. The most commonly used drug historically, and the only one actually approved by the FDA for this purpose, is chlorpromazine. This is a dopamine blocking medication more commonly prescribed for its anti-psychotic properties to treat patients with schizophrenia, but it has a wide variety of uses ranging from migraines to “brain-eating” amoeba infections. Because the dose for hiccups is considerably lower than that used for other conditions, it has a low risk of any significant side effects.
Many other drugs have been tried for hiccups, including marijuana, and some have replaced chlorpromazine as the recommended first line therapy depending on which resource you use for help deciding. Even surgical implantation of devices that stimulate either the phrenic or the vagus nerve has been attempted. It’s hard to find a negative report about any hiccup treatment because if the drug that is being investigated doesn’t help, nobody is going to want to write it up.
Hiccup home remedies
The internet is overflowing with advice on how to stop hiccups. A quick internet search reveals a seemingly-endless number of articles listing foolproof remedies and quick cures, with many overlapping with the physical maneuvers recommended as first line treatment by physicians. There are of course the classics, like eating sugar or peanut butter and breathing into a bag. Not at the same time of course. These websites often try to give scientific justifications, frequently mentioning the stimulation of the vagus nerve or the raising of CO2 levels in the blood for example.
Some home remedies are just plain silly, like drinking a glass of water after you dropped a lit match into it, or drinking water while upside down. I found several references to gulping water with your fingers jammed into your ears, and was even told this by a physician assistant in our emergency department recently. Everything supposedly works every time, or at least people remember when the hiccups stop soon after a treatment and forget the times they don’t. Of course the evidence base for any of these recommendations is as pitiful as for any other method, and they are certainly harmless if not done while driving or trying to defuse a bomb.
This 13-year-old girl just re-branded sour lollipops as a hiccup cure and will probably make millions of dollars.
Alternative medical treatment of hiccups
Like the interventions of conventional physicians for persistent and intractable hiccups, there is no good evidence to support the use of any alternative medical modality, even the popular ones. As you might imagine, the chiropractic presence on the internet lists hiccups as something they can handle with great success, because nerves. There are countless websites providing testimonials and anecdotal experiences with chiropractic. Here is a case report provided by the American Chiropractic Association where a patient with hiccups for ten days improved while also seeing a chiropractor. They also recommend icing the phrenic nerve and giving the tongue a good yank.
This holistic chiropractor/ear acupuncturist/homeopath tells us how to stop hiccups in ten seconds. PubMed yields nothing.
There are many trials looking at the use of acupuncture for persistent and intractable hiccups, none of which are randomized controlled trials. They involve the usual wide variety of acupuncture styles, such as Korean hand acupuncture, acupressure, auricular acupuncture and regular acupuncture at a variety of locations. Most are in Chinese and unavailable for review, and they are all positive of course. But don’t be fooled. I have little doubt that were a proper study with appropriate controls and blinding ever to be done, acupuncture would once again be revealed to perform no better than placebo.
Hypnotherapy is also a popular alternative treatment for hiccups, although I can’t figure out why. Again there are no controlled trials. I can’t find anything on it other than two case reports that are over 50 years old (1,2). Yet recommendations for trying hypnosis can be found everywhere, even on typically solid sources like UpToDate. This therapist can cure hiccups and provide a virtual gastric band at the same time to help with weight loss. She can even teach you how to use her techniques to increase your business and profits. I doubt it’s cheap and I doubt it’s covered by insurance.
There are many other alternative therapies aimed at stopping or at least improving cases of prolonged hiccups. You can pay this lady to perform Quantum Touch to cure your hiccups, or just annoy her while she’s in the library for a free treatment. Homeopathy has much to offer hiccup sufferers. They recommend Hyoscyamus Niger, for instance, if your hiccups only occur while urinating at night.
Although usually a brief, mild and sometimes humorous annoyance, hiccups can in rare cases be severe and protracted to the point of causing very serious sequelae. Unfortunately, they remain somewhat of a mystery and science-based therapies are lacking because of the difficulty performing large controlled trials on such a rare condition. And because even intractable cases do often resolve spontaneously, a very long list of medical therapies, home remedies and treatments provided by various alternative medical practitioners likely only have the appearance of efficacy.
Despite the fact that nobody has much to offer patients with persistent or intractable hiccups, the key difference between science-based providers and researchers, and the world of alternative medicine, is the humility to admit it. And though the irregular remedies discussed above are generally safe, patients who do not seek appropriate medical care may have delayed diagnosis and treatment of one of the possible associated serious conditions. Legitimate medical researchers will continue to work on finding more effective therapies for hiccups, while champions of these other approaches will continue to offer their theatrical placebos while refusing to evolve as new evidence emerges.