most of the time my stomach feels sick, what can this be?
Indigestion Indigestion is pain and burning in the upper abdomen, an feeling of fullness after a meal, belching, and gas. Gastritis Gastritis is an inflammation of the stomach lining, causes stomach upset, irritation, and pain. Medication reaction or side-effect Medication side effects include nausea, vomiting, stomach upset, weakness, dizziness, seizures, and more.