Gastroesophageal Reflux Disease (GERD): A High-Yield USMLE Review

GERD is the most common esophageal disorder, affecting 20-30% of the Western population. It represents a spectrum ranging from minor heartburn to complications including strictures, Barrett's esophagus, and esophageal adenocarcinoma. High-yield exam themes include recognizing atypical presentations, understanding LES pathophysiology, and knowing when to escalate to endoscopy or surgery.

Presentation

• Heartburn: retrosternal burning, worse after meals and with recumbency
• Regurgitation: effortless return of gastric contents to the mouth
• Dysphagia: suggests a complication such as stricture or severe esophagitis
• Atypical/extraesophageal symptoms: chronic nocturnal cough, laryngitis, hoarseness, asthma exacerbation, dental erosions, and non-cardiac chest pain

Diagnosis

• Clinical diagnosis based on typical symptoms of heartburn and regurgitation; a therapeutic response supports the diagnosis
• Upper endoscopy (EGD) with biopsy: evaluates for esophagitis, stricture, and Barrett's esophagus (salmon-colored mucosa/tongues of red extending above the GEJ), and confirms intestinal metaplasia when goblet cells are present
• pH-impedance monitoring: used to objectively confirm reflux, especially in PPI-refractory or atypical cases; can be performed while on therapy to clarify the diagnosis
• Screening endoscopy is recommended for chronic GERD symptoms (>5-10 years) plus risk factors (age >50, male sex, obesity, smoking, Caucasian race, family history of Barrett's or esophageal adenocarcinoma)

Management

• Lifestyle modifications: elevate the head of the bed, avoid eating within 3 hours of bedtime, weight loss if overweight, avoid trigger foods (caffeine, alcohol, fatty foods), and smoking cessation
• Proton pump inhibitors: take 30-60 minutes before meals because PPIs irreversibly bind actively secreting proton pumps, which are inserted into the canalicular membrane upon food stimulation
• Surgical fundoplication (Nissen 360°; Toupet partial): reserved for refractory symptoms, complications, or patient preference to avoid lifelong medication, with best outcomes in patients with typical symptoms, proven reflux, and normal motility
• For Barrett's esophagus without dysplasia: continue PPI and perform surveillance EGD with systematic biopsies every 3-5 years

High-yield

• GERD is the most common esophageal disorder (20-30% of the Western population)
• Transient LES relaxations (TLESRs) are the most common reflux mechanism, accounting for ~70% of episodes in GERD patients
• Chronic reflux → Barrett's esophagus (metaplasia to intestinal-type columnar epithelium with goblet cells) → esophageal adenocarcinoma (~0.3-0.5% per year risk when non-dysplastic)
• Goblet cells are required to diagnose Barrett's; columnar epithelium without goblet cells (cardiac/gastric-type) does not carry the same cancer risk
• Scleroderma esophagus (CREST) causes severe GERD from a hypotensive LES plus poor clearance, with high risk of strictures and Barrett's
• Take PPIs before meals to coincide with maximal proton pump activity; empty-stomach dosing is less effective

Pitfalls

• Anchoring on pulmonary or cardiac causes and missing GERD in patients presenting with chronic cough, hoarseness, or asthma without heartburn (representativeness bias) — up to 40% of chronic cough may be GERD-related
• Escalating PPI dose in 'refractory GERD' before verifying compliance/timing and objectively confirming the diagnosis; consider eosinophilic esophagitis, functional heartburn, rumination syndrome, achalasia, or bile reflux
• Diagnosing Barrett's based on columnar mucosa alone — goblet cells (intestinal metaplasia) are required
• Attributing progressive dysphagia with weight loss to GERD; progressive solids-to-liquids dysphagia with weight loss is cancer until proven otherwise