Gastroesophageal reflux is a physical condition in which acid from the stomach flows backward up into the esophagus. People will experience heartburn symptoms when excessive amounts of acid reflux into the esophagus. Many describe heartburn as a feeling of burning discomfort, localized behind the breastbone, that moves up toward the neck and throat. Some even experience the bitter or sour taste of the acid in the back of the throat. The burning and pressure symptoms of heartburn can last for several hours and often worsen after eating food. All of us may have occasional heartburn. However, frequent heartburn (two or more times a week), food sticking, blood or weight loss may be associated with a more severe problem known as gastroesophageal reflux disease or GERD.