What are the medical causes of hiccups?

Medical Causes of Hiccups

Hiccups are caused by a variety of medical conditions affecting the complex reflex arc between peripheral receptors and the brainstem, with gastroesophageal reflux disease (GERD) being the most common identifiable cause. 1

Pathophysiology

• Hiccups result from sudden erratic diaphragmatic and intercostal muscle contractions immediately followed by laryngeal closure, producing the characteristic "hic" sound 2
• A reflex arc involving peripheral phrenic, vagal and sympathetic pathways with central midbrain modulation is responsible for hiccup generation 2
• Any irritation or disruption along this pathway can trigger hiccups 2

Classification by Duration

• Acute hiccups: Self-limited episodes lasting less than 48 hours 3
• Persistent hiccups: Episodes lasting beyond 48 hours 2
• Intractable hiccups: Episodes lasting longer than 2 months 2

Gastrointestinal Causes

• Gastroesophageal reflux disease (GERD) - most common cause of persistent hiccups 1, 4
• Severe erosive esophagitis - can cause protracted hiccups resistant to neurologic medications 4
• Gastritis and stomach inflammation 3
• Overdistension of the stomach - most common cause of acute hiccups 3
• Pancreatitis 2
• Hepatitis or liver disease 2

Neurological Causes

• Stroke affecting the brainstem or midbrain 2
• Space-occupying lesions (tumors, abscesses) in the central nervous system 2
• Multiple sclerosis 2
• Traumatic brain injury 2
• Compression of the phrenic nerve 2

Cardiovascular Causes

• Myocardial ischemia 2
• Pericarditis 5
• Pericardial effusion - hiccups can be a non-specific symptom due to compression of the phrenic nerve 5

Pulmonary Causes

• Pneumonia 2
• Pleuritis 2
• Pulmonary embolism 2
• Asthma 2

Infectious Causes

• Herpes zoster infection affecting the vagus or phrenic nerve 2
• Tuberculosis - particularly in endemic areas 2
• Systemic infections with fever 3

Metabolic/Toxic Causes

• Uremia in kidney disease 2
• Electrolyte imbalances (particularly hyponatremia, hypocalcemia) 2
• Alcohol consumption 2
• Toxic ingestions 2

Medication-Induced Causes

• Anti-Parkinson medications 2
• Anesthetic agents 2
• Steroids 2
• Chemotherapy agents 2
• Benzodiazepines 2

Psychogenic Causes

• Stress and anxiety disorders 2, 3
• Conversion disorder 2
• Malingering 2

Diagnostic Approach

• For acute, self-limited hiccups lasting less than 48 hours, extensive workup is usually unnecessary 3
• For persistent or intractable hiccups, a thorough evaluation is warranted to identify underlying causes 3
• Upper endoscopy should be considered to evaluate for GERD and erosive esophagitis 4
• Neuroimaging (CT or MRI) may be necessary if central nervous system causes are suspected 2
• Basic laboratory studies to evaluate metabolic causes 2

Treatment Considerations

• Treatment should target the underlying cause whenever possible 3
• For GERD-related hiccups, proton pump inhibitors (PPIs) should be first-line therapy 1, 4
• For neurologically-mediated hiccups, medications such as baclofen, gabapentin, or chlorpromazine may be effective 2
• Non-pharmacological approaches including nerve blockade, pacing, and breathing techniques can be considered for refractory cases 2

Persistent or intractable hiccups should be viewed as a potential sign of serious underlying pathology and warrant thorough investigation, particularly when they fail to respond to initial interventions 3.