Heartburn: Causes, Mechanisms, and Risk Factors

Heartburn is a burning chest sensation caused by reflux of acidic gastric juice into the esophagus. The stomach produces gastric juice to digest food, but when it contacts the sensitive esophageal lining, irritation and inflammation result.

The Role of the Lower Esophageal Sphincter (LES)

Normally, the LES acts as a valve preventing stomach contents from flowing backward. Heartburn occurs when the LES weakens or relaxes inappropriately.

Contributing Factors

• Hiatal hernia: Part of the stomach protrudes through the diaphragm, weakening the LES.
• Increased abdominal pressure: Obesity, pregnancy, certain medications.
• Dietary triggers: Spicy foods, fatty foods, alcohol, caffeine.
• Smoking: Damages the LES and impairs its function.
• Delayed gastric emptying: Conditions like gastroparesis or diabetes increase stomach pressure.

When to See a Doctor

Persistent or severe heartburn may indicate an underlying condition such as a peptic ulcer or gastroesophageal reflux disease (GERD). Seek medical evaluation for proper diagnosis and treatment.