Belching is the act of bringing up air from the stomach.
Burping; Eructation; Gas - belching
Belching is most often a normal process. The purpose of belching is to release air from the stomach. Every time you swallow, you also swallow air, along with fluid or food.
The buildup of air in the upper stomach causes the stomach to stretch. This triggers the muscle at the lower end of the esophagus (the tube that runs from your mouth to the stomach) to relax. Air is allowed to escape up the esophagus and out the mouth.
Excessive or repeated belching may be caused by swallowing air without realizing it (aerophagia).
Belching may last longer or be more forceful depending on what is causing it. Symptoms such as nausea, dyspepsia, and heartburn may be relieved by belching.
Pressure caused by the unconscious swallowing of air
George F. Longstreth, MD, Department of Gastroenterology, Kaiser Permanente Medical Care Program, San Diego, California. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.