What causes constant hiccups?

Causes of Constant Hiccups

Constant hiccups are most commonly caused by gastroesophageal reflux disease (GERD), but can also result from central nervous system disorders, thoracic pathologies, medication side effects, or metabolic disturbances.

Pathophysiology of Hiccups

Hiccups (singultus) result from a reflex arc involving:

• Afferent limb: Vagus and phrenic nerves
• Central processor: Hiccup center in the midbrain
• Efferent limb: Phrenic nerve to diaphragm and intercostal muscles

The characteristic "hic" sound occurs from sudden inspiration against a closed glottis.

Common Causes of Hiccups

Gastrointestinal Causes (Most Common)

• GERD: The leading cause of persistent hiccups 1
• Gastritis or peptic ulcer disease
• Gastric distention
• Abdominal surgery

Central Nervous System Causes

• Stroke
• Brain tumors
• Intracranial hemorrhage
• Multiple sclerosis

Thoracic Causes

• Myocardial infarction
• Pericarditis
• Pneumonia
• Pleural irritation
• Post-obstructive pulmonary edema 2

Metabolic/Systemic Causes

• Uremia/renal failure
• Electrolyte imbalances
• Alcohol consumption
• Hyperventilation syndrome 2

Medication-Induced Causes

• Anesthetic agents
• Steroids
• Chemotherapy
• Anti-Parkinson medications 3

Classification by Duration

1. Acute hiccups: Episodes lasting less than 48 hours
2. Persistent hiccups: Episodes lasting 48 hours to 2 months
3. Intractable hiccups: Episodes lasting longer than 2 months 3

Diagnostic Approach for Persistent Hiccups

For hiccups lasting more than 48 hours, a systematic evaluation is warranted:

1. Detailed history focusing on:

   • Medication review
   • Recent procedures or surgeries
   • Gastrointestinal symptoms
   • Neurological symptoms

2. Physical examination with attention to:

   • Abdominal examination
   • Neurological assessment
   • Cardiopulmonary evaluation

3. Initial diagnostic tests:

   • Upper GI endoscopy (first-line investigation due to high prevalence of GERD) 4
   • pH monitoring
   • Chest X-ray
   • Basic metabolic panel

4. Advanced imaging (if initial evaluation inconclusive):

   • Brain CT or MRI
   • Chest CT
   • Abdominal ultrasound

Treatment Considerations

For persistent hiccups, treatment should target the underlying cause:

• GERD: Proton pump inhibitors should be first-line therapy 1
• CNS causes: Treat underlying neurological condition
• Medication-induced: Consider medication adjustment

For symptomatic treatment of intractable hiccups:

• First-line pharmacotherapy: Chlorpromazine 25-50 mg three to four times daily 5, 3
• Alternative medications: Baclofen, gabapentin, metoclopramide

Key Points to Remember

• Most hiccup episodes are benign and self-limiting
• Persistent hiccups (>48 hours) warrant medical evaluation as they may indicate serious underlying pathology
• GERD is the most common cause of persistent hiccups and should be ruled out first
• Pharmacological treatment should be reserved for persistent or intractable cases
• Physical maneuvers (stimulating the pharynx, disrupting respiratory rhythm) may help terminate acute hiccup episodes 6

Emerging Treatments

Recent research suggests the HAPI technique (Hiccup relief using Active Prolonged Inspiration) may be effective for acute hiccups. This involves maximal inspiration followed by continued inspiratory effort with an open glottis for 30 seconds 7.