Gastritis is a general term for a group of conditions with one thing in common: Inflammation of the lining of the stomach. The inflammation of gastritis is most often the result of infection with the same bacterium that causes most stomach ulcers or the regular use of certain pain relievers. Drinking too much alcohol also can contribute to gastritis.

Gastritis may occur suddenly (acute gastritis) or appear slowly over time (chronic gastritis). In some cases, gastritis can lead to ulcers and an increased risk of stomach cancer. For most people, however, gastritis isn't serious and improves quickly with treatment.

Symptoms
The signs and symptoms of gastritis include:

Gnawing or burning ache or pain (indigestion) in your upper abdomen that may become either worse or better with eating
Nausea
Vomiting
A feeling of fullness in your upper abdomen after eating.

Complications
Left untreated, gastritis may lead to stomach ulcers and stomach bleeding. Rarely, some forms of chronic gastritis may increase your risk of stomach cancer, especially if you have extensive thinning of the stomach lining and changes in the lining's cells.