Gastroesophageal Reflux Disease

In GERD, the lower esophageal sphincter (LES) fails due to reduced tone, spontaneous relaxations, or impaired peristalsis. Risk factors include obesity, aging, pregnancy, and sliding hiatal hernia, which disrupts diaphragm support. Medications like nicotine, anticholinergics, and calcium channel blockers further weaken LES tone, making reflux more likely.

Prolonged exposure to refluxate—acid, pepsin, and bile—damages the esophageal mucosa, causing inflammation, erosion, and immune cell infiltration. Chronic inflammation leads to fibrosis and thickening of the esophageal wall. This damage reduces LES function further, perpetuating the disease cycle and potentially causing Barrett esophagus.

Common GERD symptoms include heartburn, acid regurgitation, chest pain, difficulty swallowing (dysphagia), cough, and hoarseness. Symptoms often worsen after meals, when lying down, or during activities that increase intra-abdominal pressure such as coughing or straining. These manifestations reflect ongoing mucosal irritation.

Barrett esophagus occurs when chronic GERD causes the normal squamous epithelium of the esophagus to be replaced by specialized columnar cells. This condition significantly raises the risk of developing esophageal adenocarcinoma, particularly in men and smokers, making it a serious long-term complication.

Increased intra-abdominal pressure from coughing, pregnancy, or obesity worsens reflux by pushing stomach contents upward. A sliding hiatal hernia disrupts the angle of His and diaphragm support, further compromising the LES barrier. Delayed gastric emptying and poor esophageal motility also promote reflux episodes.

Chronic GERD can cause esophageal fibrosis, strictures resulting in progressive dysphagia, bleeding, and aspiration pneumonia. Barrett esophagus represents a serious complication with increased adenocarcinoma risk. Fibrotic healing thickens the esophageal wall, further reducing LES function and worsening clinical manifestations and complications.

After meals, gastric distention triggers inappropriate LES relaxations, allowing reflux. Lying down eliminates gravity's protective effect on esophageal clearance, allowing stomach acid to remain in contact with the esophageal lining longer. Both positions reduce the esophagus's ability to clear refluxate, intensifying symptoms.