Hiccups
Exam Tips
- Classify by duration in OSCE/viva: acute <48 h, persistent >48 h, intractable >1 month.
- If hiccups continue during sleep, this supports an organic (non-psychogenic) cause.
- In history, always screen respiratory, GI, neurological, medication and cancer red-flag symptoms.
- In persistent cases, state baseline tests first (FBC, U&Es/calcium, CXR, ECG) then targeted imaging/endoscopy by clues.
- Mention reversible triggers and bedside manoeuvres, but show escalation logic to specialist care when >48 h or red flags.
- For prescribing stations, include safety: domperidone and QT risk, metoclopramide duration limit, and avoid abrupt baclofen withdrawal.
Definition
Hiccups (singultus) are involuntary, repetitive spasmodic contractions of inspiratory muscles (mainly diaphragm and intercostals) followed by abrupt glottic closure, producing the characteristic “hic” sound. Acute hiccups are usually benign and self-limiting (<48 hours), while persistent hiccups last >48 hours and intractable hiccups last >1 month, usually prompting assessment for an underlying pathological cause.
Pathophysiology
Hiccups arise from activation of a reflex arc with afferent input via the vagus nerve, phrenic nerve, and thoracic sympathetic fibres; central processing in the brainstem (medullary respiratory network); and efferent output mainly through the phrenic nerve to the diaphragm and accessory inspiratory muscles. Sudden inspiratory contraction generates rapid airflow, then reflex glottic closure (via recurrent laryngeal pathways) creates the hiccup sound. Persistent episodes often reflect ongoing irritation anywhere along this arc (for example gastro-oesophageal inflammation, mediastinal/thoracic pathology, CNS lesions, or metabolic disturbance). Image reference: see a labelled "hiccup reflex arc" diagram in respiratory neurophysiology texts (brainstem respiratory control figure).
Risk Factors
- Large meals, gastric distension, aerophagia, carbonated drinks
- Alcohol excess and smoking
- Sudden temperature shifts (for example hot/cold drinks, cold shower)
- Emotional stress, excitement, anxiety
- GORD/reflux symptoms and hiatus hernia
- Advanced malignancy (including thoracic, upper GI, pancreatic, hepatobiliary, mediastinal, cerebral)
- Neurological disease (stroke, intracranial tumour, multiple sclerosis, encephalitis/meningitis)
- Parkinson's disease
- Metabolic derangement (uraemia, hyponatraemia, hypokalaemia, hypocalcaemia, alkalosis)
- Medication exposure (for example dexamethasone, benzodiazepines such as diazepam, dopamine agonists, some antiepileptics, methyldopa)
Clinical Features
Symptoms
- Repetitive involuntary hic sounds and diaphragmatic jerks
- Persistence beyond 48 hours or recurrent prolonged attacks (>1 hour)
- Heartburn/reflux, dysphagia, odynophagia, abdominal pain, vomiting, jaundice
- Respiratory symptoms (dyspnoea, cough, sputum, pleuritic chest pain)
- Neurological symptoms (seizures, focal sensory or motor deficits)
- Systemic red flags (fever, night sweats, unintentional weight loss)
- Sleep disturbance, poor oral intake, fatigue, social embarrassment/psychological distress
Signs
- Observed intermittent diaphragmatic contractions with characteristic hic sound
- Weight loss or dehydration in prolonged cases
- ENT findings (pharyngitis, laryngitis, foreign body in external auditory canal, goitre/neck mass)
- Respiratory signs (wheeze, crackles, pleural signs, reduced air entry)
- Abdominal signs (hepatomegaly, splenomegaly, tenderness, palpable aneurysm, peritonism/acute abdomen)
- Neurological abnormalities suggesting central lesion or meningism
- Signs of underlying cardiopulmonary disease (for example arrhythmia, pericarditic features)
Investigations
Management
Lifestyle Modifications
- Identify and avoid precipitating factors (overeating, alcohol, fizzy drinks, smoking, abrupt temperature changes, stress triggers)
- Simple interruptive manoeuvres during attacks: breath-hold, Valsalva, paper-bag rebreathing (short supervised use only), sipping iced water, swallowing granulated sugar, knees-to-chest, tongue pull
- Treat identifiable underlying cause promptly (for example infection, reflux, metabolic disturbance, CNS/cardiopulmonary pathology)
- Escalate if >48 hours, recurrent prolonged episodes, red flags, or significant functional impact
Pharmacological Treatment
Dopamine antagonists (first-line specialist drug options)
- Chlorpromazine 25-50 mg orally three to four times daily (if severe, specialist may use slow IV/IM dosing), usually short course 7-10 days
- Metoclopramide 10 mg orally/IV up to three times daily (off-label for hiccups; usual max duration 5 days)
Monitor for hypotension/sedation with chlorpromazine; avoid chlorpromazine in significant CNS depression or severe hypotension. Metoclopramide carries extrapyramidal risk (higher in young adults), avoid in GI obstruction/perforation/haemorrhage and Parkinsonism; limit duration.
GABA-ergic and neuromodulating agents (persistent/refractory cases)
- Baclofen 5 mg three times daily, titrate cautiously up to 20 mg three times daily if needed
- Gabapentin 100-300 mg at night or three times daily, titrated according to response/tolerance (off-label)
Baclofen may cause drowsiness, weakness, and withdrawal phenomena; do not stop abruptly. Gabapentin can cause dizziness/somnolence and confusion, especially in frailty/renal impairment; adjust dose for renal function.
Palliative-care and cause-directed adjuncts
- Omeprazole 20 mg once daily for reflux-associated symptoms
- Domperidone 10 mg up to three times daily for short-term use (typically up to 7 days)
- Dexamethasone 4-8 mg orally in the morning in selected cancer-related compression/irritation; stop after 1 week if ineffective
- Haloperidol 500 micrograms-1 mg every 8 hours orally; maintenance 1-3 mg at night
- Levomepromazine 3-6 mg orally at bedtime
- Nifedipine 5-20 mg every 8 hours if required
Domperidone is contraindicated with known QT prolongation, significant cardiac disease, or concomitant QT-prolonging/CYP3A4-inhibiting drugs. Dexamethasone can worsen glycaemia/infection risk and itself may trigger hiccups in some patients. Avoid levomepromazine or nifedipine in hypotension.
Surgical / Interventional
- Specialist interventions for refractory severe morbidity: phrenic nerve block or surgical interruption (rare, last-line)
- Procedure-based reflex interruption (for example nasopharyngeal stimulation) may be attempted by experienced clinicians
Complications
- Gastro-oesophageal reflux due to impaired oesophageal motility and lower sphincter function
- Weight loss, dehydration, and malnutrition
- Sleep disruption and daytime fatigue
- Psychological distress and reduced quality of life
- Cardiac arrhythmias from severe repetitive diaphragmatic contractions
- In severe inpatient cases: interference with ventilation/procedures and risk of wound dehiscence
Prognosis
Acute benign hiccups usually resolve spontaneously and have an excellent prognosis. Persistent or intractable hiccups can continue for months to years if the driver is not addressed, but may improve with successful treatment of the underlying cause and targeted symptomatic therapy; occasional abrupt spontaneous remission is described.
Sources & References
🏥BMJ Best Practice(1)
✅NICE Guidelines(1)
- Hiccups[overview]