Where the esophagus is connected to the stomach, the lower esophagus sphincter is supposed to restrict traffic one way. Occasionally, acid in the stomach will work its way back into the esophagus and the will irritate its sensitive lining. This can cause a burning sensation and, depending on how much acid has been refluxed out of the stomach, can cause severe burning in the chest, as well as other symptoms that can be confused with a heart attack.

What is acid reflux is typically worse when lying down as the acid is allowed to remain in the esophagus longer. It is possible that the reflux occurs numerous times throughout the day, but while standing, gravity will help it find its way back into the stomach. Additionally, natural antacids in saliva will counteract the acid and help wash it back into the stomach.

Hiatal Hernia May Contribute To Reflux

In some persons suffering GERD, also have a hiatal hernia, although not all will have this problem. The stomach is attached to the esophagus and is separated from the upper abdomen by the diaphragm. With a hiatal hernia, the portion of the stomach to which the esophagus is attached can be pushed upwards through the diaphragm. This also results in reflux of acid from the stomach, resulting in a several burning sensation. For those with this condition, what is acid reflux is sometimes exacerbated by the hernia.

Most reflux actions during the day occur soon after eating and being upright helps keep everything in the stomach where it is supposed to be. However, overeating can also contribute to what is acid reflux. Think of the stomach as a tube of toothpaste with the lid loose. Squeezing the tube in the center will result in the paste exiting the tube through the path of least resistance, in this case the loose lid.

The loose lid is representative of a weakened lower esophagus sphincter allowing acid to reflux into the esophagus, causing heartburn and other symptoms of what is acid reflux.