What causes burping?

Causes of Burping (Belching)

Burping occurs through two distinct mechanisms: gastric belching (involuntary air release from the stomach) and supragastric belching (voluntary behavioral pattern where air is sucked into the esophagus and immediately expelled), with the latter being far more common in patients complaining of excessive belching. 1

Primary Mechanisms of Belching

Gastric Belching (Involuntary)

• Physiological mechanism: Spontaneous transient relaxation of the lower esophageal sphincter allows air to move from the stomach through the esophagus, followed by upper esophageal sphincter relaxation for oral expulsion 1
• Associated conditions: Occurs in up to 50% of patients with gastroesophageal reflux disease (GERD) 1
• Normal function: This is the body's natural way to vent swallowed air that has accumulated in the stomach 2

Supragastric Belching (Voluntary/Behavioral)

• Two distinct methods exist: 1
  • Air-suction method: Air flows through a pressure gradient from upper esophageal sphincter relaxation that occurs before air enters the esophagus (opposite sequence from gastric belching) 1
  • Air-injection method: Elevated pharyngeal pressure from tongue base contraction pushes air into the upper esophagus, similar to deliberate burping in healthy individuals—this is a learned behavior 1
• Prevalence: Occurs in up to 3.4% of patients with upper gastrointestinal symptoms 1
• Key distinguishing feature: Supragastric belching stops during sleep, distraction, or when speaking, proving psychological factors modulate its occurrence 1

Associated Medical Conditions

Gastrointestinal Disorders

• GERD: Belching reported in up to 50% of GERD patients, with gastric belching being the predominant type 1
• Functional dyspepsia: Commonly presents with belching as an associated symptom 1
• Gastroparesis: Impaired gastric accommodation can lead to belching symptoms 1

Structural Causes

• Hiatal hernias and paraesophageal hernias can cause belching 1
• Post-Nissen fundoplication: Impaired gastric accommodation leads to belching and dyspepsia symptoms 1

Psychological Factors

• Anxiety: Strongly associated with supragastric belching 1
• Conditioned behavioral response: Patients may develop belching as a learned behavior to reduce bloating sensations by releasing air and reducing gastric wall tension 1
• Life stressors: Psychosocial triggering factors and conditioned responses to physical symptoms contribute to excessive belching 1

Aerophagia (Distinct from Belching)

• Mechanism: Excessive air swallowing increases intragastric and intestinal gas 1
• Key difference: In aerophagia, excess air moves to the intestines and colon, causing flatulence and bloating as main symptoms rather than excessive belching 1
• Diagnostic clue: Visible excessive intestinal gas on abdominal X-rays 3

Prevalence

• Overall belching disorders: 1% of adults globally based on Rome IV criteria 1
• When considered bothersome: Defined as disrupting usual activities and occurring more than 3 days per week 1

Clinical Pitfalls to Avoid

• Do not confuse supragastric belching with gastric belching: The former requires behavioral therapy, while the latter may respond to GERD treatment with PPIs if reflux is present 4
• Do not assume all belching is GERD-related: Supragastric belching that occurs before reflux episodes does not respond to PPI therapy 1
• Do not overlook the behavioral component: Supragastric belching is a learned behavior that requires cognitive behavioral therapy or speech therapy, not acid suppression 5
• Recognize pregnancy as a potential cause: Belching can occur during pregnancy as a normal physiological response 1