The gastric pain generally starts as a burning sensation in the upper abdomen and moves up into the chest. It usually occurs after eating or while lying down or bending over and is relieved by antacids, whereas chest pain, if accompanied with a sudden feeling of pressure, squeezing, tightness, crushing under your breastbone, spreading to your jaw, left arm, or back is generally an alarm of concern as such chest pain are related to heart or angina.