Acid reflux, also known as GERD (Gastroesophageal Reflux Disease), is a chronic condition where stomach acid flows back into the esophagus. This backwash (reflux) can irritate the lining of the esophagus and lead to persistent symptoms if not properly managed. GERD is common and treatable, but if left unchecked, it can cause long-term complications such as esophagitis or Barrett’s esophagus.