Heartburn is characterized by a painful burning sensation that originates from the chest and spreads toward the throat. The main cause of heartburn is back flow of stomach acid into the esophagus (food pipe), leading to irritation in the unprotected esophagus. It is a very common symptom of the gastro esophageal reflux disease. It mainly occurs after taking meals, in the evening, or while lying down, and can last for several hours.
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Causes of Heartburn (Acid Reflux)