Hiccups are repeated involuntary spasms of the diaphragm followed by sudden closure of the glottis, which checks the inflow of air and causes the characteristic sound. Transient episodes are very common. Persistent (> 2 days) and intractable (> 1 month) hiccups are uncommon but quite distressing.
Etiology of Hiccups
Hiccups follow irritation of afferent or efferent diaphragmatic nerves or of medullary centers that control the respiratory muscles, particularly the diaphragm. Hiccups are more common among men.
The cause of hiccups is generally unknown, but transient hiccups are often caused by the following:
Gastric distention
Alcohol consumption
Swallowing hot or irritating substances
Persistent and intractable hiccups have myriad causes (see table Some Causes of Intractable Hiccups).
Evaluation of Hiccups
History
History of present illness should note duration of hiccups, remedies tried, and relationship of onset to recent illness or surgery.
Review of systems seeks concomitant gastrointestinal (GI) symptoms such as gastroesophageal reflux and swallowing difficulties; thoracic symptoms such as cough or chest pain; and any neurologic symptoms.
Past medical history should query known GI and neurologic disorders, and should include details concerning alcohol use.
Physical examination
Examination is usually unrewarding but should seek signs of chronic disease (eg, cachexia). A full neurologic examination is important.
Red flags
The following is of particular concern:
Neurologic symptoms or signs
Interpretation of findings
Few findings are specific. Hiccups after alcohol consumption or surgery may well be related to those events. Other possible causes (see table Some Causes of Intractable Hiccups) are both numerous and rarely a cause of hiccups.
Testing
No specific evaluation is required for acute hiccups if routine history and physical examination are unremarkable; abnormalities are pursued with appropriate testing.
Patients with hiccups of longer duration and no obvious cause should have testing, including serum electrolytes, blood urea nitrogen (BUN) and creatinine, chest radiograph, and ECG. Upper GI endoscopy and esophageal pH monitoring should be considered. If these are unremarkable, brain MRI and chest CT may be done.
Treatment of Hiccups
Identified problems are treated (eg, proton pump inhibitors for gastroesophageal reflux disease, dilation for esophageal stricture).
For symptom relief, some simple physical maneuvers can be tried, but they may not be effective and lack robust evidence for their use. For example, PaCO2 can be increased and diaphragmatic activity can be inhibited by a series of deep breath-holds or by breathing deeply in to and out of a paper bag. (CAUTION: Plastic bags can cling to the nostrils and should not be used.) Vagal stimulation by pharyngeal irritation (eg, swallowing dry bread, granulated sugar, or crushed ice; applying traction on the tongue; stimulating gagging) may work. Numerous other folk remedies exist.
Persistent hiccups are often recalcitrant to treatment (1
In intractable cases, the phrenic nerve may be blocked by small amounts of 0.5% procaine solution, with caution being taken to avoid respiratory depression and pneumothorax. Even bilateral phrenicotomy does not cure all cases.
Treatment reference
1. Reichenbach ZW, Piech GM, Malik Z. Chronic Hiccups. Curr Treat Options Gastroenterol. 2020;18(1):43-59. Published 2020 Jan 23. doi:10.1007/s11938-020-00273-3
Key Points
The cause is usually unknown.
Rarely, a serious disorder is present.
Evaluation is typically unrewarding but should be pursued for hiccups of long duration.
Numerous remedies with limited effectiveness exist, none with clear superiority.
