What is acid reflux?

Acid reflux involves a faulty valve in the digestive system. It occurs when a valve called the lower esophageal sphincter releases at the wrong time, sending stomach acids back into the esophagus. This creates a burning feeling in the throat or the chest. Most cases can be relieved with a prescription or an over-the-counter treatment; see a doctor to avoid permanent damage to the esophageal lining.

Acid reflux, or Gastroesophageal reflux (GER), describes the physiologic condition in which stomach contents come up from the stomach into the esophagus where it doesn't belong.  It's important to understand that this definition says nothing about being sick or miserable.  That's because reflux is a physiologic process, which means that it's normal.  All of us experience reflux at various times in the day but most of us are unaware when it occurs.  

But sometimes the flow of stomach contents into the esophagus can create problems.  Gastric contents can irritate the esophagus and upper airway creating symptoms of cough, throat clearing, hoarseness, wheezing, and difficulty swallowing.  When reflux creates problems we refer to it as gastroesophageal reflux disease (GERD), or pathologic reflux.  

Acid reflux is the backup of stomach acid into the esophagus, the muscular tube that connects the throat to the stomach. It may cause burning pain in the esophagus.

Acid reflux may occur because of weakness in the ring of muscle (lower esophageal sphincter, or LES) that controls the flow of food from the esophagus into the stomach. Frequent acid reflux can lead to irritation of the esophagus (esophagitis), narrowing of the esophagus, or development of sores (ulcers) in the esophagus. Long-term exposure of the esophagus to stomach acid causes the cells that line the inside of the esophagus to be replaced by cells similar to those that line the inside of the stomach (Barrett's esophagus).