When people swallow food or fluid, they also swallow air. The air begins to build up in the upper stomach causing the stomach to stretch. When this happens, the lower part of the esophagus relaxes to let out the excess air, as stated by MedlinePlus.
There are several ways to reduce belching. These include eating and drinking slowly, avoiding carbonated drinks, avoiding chewing gum and hard candy, quitting smoking and treating heartburn, according to Mayo Clinic.Learn more about Pain & Symptoms