Gastroesophageal reflux disease (GERD) is a condition in which the esophagus becomes irritated or inflamed because of acid backing up from the stomach. The esophagus or food pipe is the tube stretching from the throat to the stomach. When food is swallowed, it travels down the esophagus.
The stomach produces hydrochloric acid after a meal to aid in the digestion of food.
- The inner lining of the stomach resists corrosion by this acid. The cells that line the stomach secrete large amounts of protective mucus.
- The lining of the esophagus does not share these resistant features and stomach acid can damage it.
- The esophagus lies just behind the heart, so the term heartburn was coined to describe the sensation of acid burning the esophagus (see Media file 1).
Normally, a ring of muscle at the bottom of the esophagus, called the lower esophageal sphincter, prevents reflux (or backing up) of acid.
- This sphincter relaxes during swallowing to allow food to pass. It then tightens to prevent flow in the opposite direction.
- With GERD, however, the sphincter relaxes between swallows, allowing stomach contents and corrosive acid to well up and damage the lining of the esophagus.
GERD affects nearly one third of the adult population of the United States to some degree at least once a month. Almost 10% of adults experience GERD weekly or daily. Not just adults are affected; even infants and children can have GERD.