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Hiccups (hiccough, singultus) 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 mo) hiccups are uncommon but quite distressing.

Etiology

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.

Cause 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 4: Approach to the Patient with Upper GI Complaints: Some Causes of Intractable Hiccups).

Table 4
Some Causes of Intractable Hiccups Category Examples Esophageal Gastroesophageal reflux disease Other esophageal disorders Abdominal Abdominal surgery Bowel diseases Gallbladder disease Hepatic metastases Hepatitis Pancreatitis Pregnancy Thoracic Diaphragmatic pleurisy Pericarditis Pneumonia Thoracic surgery Other Alcoholism Posterior fossa tumors or infarcts Uremia

Evaluation

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 GI symptoms such as gastroesophageal reflux and swallowing difficulties; thoracic symptoms such as cough, fever, or chest pain; and any neurologic symptoms.

Past medical history should query known GI and neurologic disorders. A drug history 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 4: Approach to the Patient with Upper GI Complaints: 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, probably including serum electrolytes, BUN and creatinine, chest x-ray, and ECG. Upper GI endoscopy and perhaps esophageal pH monitoring should be considered. If these are unremarkable, brain MRI and chest CT may be done.

Treatment

Identified problems are treated (eg, proton pump inhibitors for gastroesophageal reflux disease, dilation for esophageal stricture).

For symptom relief, many simple measures can be tried, although none are more than slightly effective: 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. Many drugs have been used in anecdotal series. Baclofen Some Trade Names
LIORESAL
Click for Drug Monograph
, a γ‑aminobutyric acid agonist (5 mg po q 6 h increasing to 20 mg/dose), may be effective. Other drugs include chlorpromazine Some Trade Names
THORAZINE
Click for Drug Monograph
10 to 50 mg po tid as needed, metoclopramide Some Trade Names
REGLAN
Click for Drug Monograph
10 mg po bid to qid, and various anticonvulsants (eg. gabapentin Some Trade Names
NEURONTIN
Click for Drug Monograph
). Additionally, an empiric trial of proton pump inhibitors may be given. For severe symptoms, chlorpromazine Some Trade Names
THORAZINE
Click for Drug Monograph
25 to 50 mg IM or IV can be given. 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.

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 exist, none with clear superiority (or perhaps even effectiveness).

Last full review/revision March 2008 by Norton J. Greenberger, MD

Content last modified March 2008