Hiccups (singultus): causes and treatment

What a hiccup is

A hiccup is an involuntary spasm of the inspiratory muscles, mainly the diaphragm. The glottis then closes suddenly, about 30 to 40 ms after inspiration starts. That closure produces the sound. The afferent limb of the reflex runs through the phrenic and vagus nerves and the thoracic sympathetic chain. Most identifiable causes irritate, inflame or injure one of these nerves (Tintinalli's Emergency Medicine, Ch. 62, "Hiccups").

Classification by duration

Benign or acute: under 48 hours.
Persistent: over 48 hours.
Intractable: over 1 month.

Causes

Acute and self-limited

Gastric distension from a large meal, carbonated drinks or swallowed air.
Alcohol. It loosens the link between inspiration and glottic closure, so other triggers set off the reflex more easily.
Excessive smoking.
Sudden change in environmental temperature.
Psychogenic causes.

Persistent or intractable (Tintinalli's Table 62-5; Sleisenger and Fordtran's; Das, Clinical Surgery)

Central nervous system: structural lesions, tumours, stroke (lateral medullary infarction), and posterior fossa or medullary compressive lesions. Pathologic hiccups are more common in men (Plum and Posner's).
Vagal or phrenic nerve irritation:
- A foreign body in the ear canal (often a hair) touching the tympanic membrane. This is rare but easily treated.
- Neck or mediastinal masses.
- Thoracic disease.
Diaphragmatic or abdominal irritation:
- Gastric dilatation.
- Paralytic ileus or intestinal obstruction.
- Subphrenic abscess.
- Peritonitis.
- Reflux or esophageal disease.
Metabolic: uraemia (advanced renal failure), hyperglycaemia, hyponatraemia.
Drugs: dexamethasone and other corticosteroids, and chemotherapy agents. General anaesthesia can also trigger hiccups.
Postoperative: after thoracic, abdominal, urologic or neurosurgical procedures. After abdominal surgery, look for a subphrenic abscess or acute gastric dilatation before assuming a benign cause.

Evaluation

Look for a trigger, including medicines.
Check whether the hiccups continue during sleep. Stopping in sleep suggests a psychogenic cause, but this is not absolute.
Examine the external auditory canal.
Get a chest X-ray for chronic hiccups.
Order U&E, glucose and sodium, and consider CNS imaging if no cause is found.
Fluoroscopy showing unilateral diaphragm movement suggests focal phrenic nerve injury.

Treatment

1. Treat the cause

Remove an ear foreign body.
Decompress the stomach with a nasogastric tube for gastric dilatation or ileus.
Treat uraemia, electrolyte problems, abscess or peritonitis.
Stop or change the offending drug.

2. Physical maneuvers for acute episodes

Swallow a teaspoon of dry granulated sugar.
Sip ice water or drink water quickly.
Hold your breath, or rebreathe into a paper bag.

These maneuvers work by stimulating the pharynx, which blocks the vagal part of the reflex arc. No single method is clearly better than the others (Tintinalli's; Sleisenger and Fordtran's).

3. Drugs for persistent or intractable hiccups (Tintinalli's Table 62-7)

Drug	ED dose	Maintenance
Chlorpromazine (only FDA-approved agent)	25-50 mg IV, repeat in 2-4 h	25-50 mg PO 3-4 times daily
Metoclopramide	10 mg IV/IM	10-20 mg PO three times daily for 10 days
Haloperidol	2-5 mg IM	2-4 mg PO three times daily
Nifedipine	10-20 mg PO	10-20 mg PO 3-4 times daily
Valproic acid	15 mg/kg PO	15 mg/kg PO three times daily
Baclofen	10 mg PO	10 mg three times daily, titrated up to 75 mg/day
Gabapentin	100 mg	100 mg three times daily, titrated up to 120 mg/day

Chlorpromazine and metoclopramide act within about 30 minutes.
Both can cause extrapyramidal effects. Chlorpromazine can also cause hypotension.
Nifedipine, valproate, baclofen and gabapentin are usually second-line options.
Other agents reported to work include quinidine, phenytoin and sertraline.
Refractory cases have been managed with acupuncture, phrenic nerve block or crush, or an implantable diaphragmatic pacemaker. The evidence for all of these is poor (Sleisenger and Fordtran's).

Recent evidence

A 2026 systematic review in palliative care found that gabapentin and baclofen were the most frequently reported effective agents. It also found the evidence to be of very low certainty, with likely publication bias. It suggests aiming for symptom control rather than cure. This agrees with the textbook position that evidence is thin. Two other recent reviews cover antipsychotics for hiccups and perioperative hiccups. I only read the abstract of the first one. I did not review the other two in detail.

Drug doses are from Tintinalli's. Check them against local protocols and adjust for renal function and age before prescribing.

This is a shared conversation. Sign in to Orris to start your own chat.