Gastritis usually develops when your stomach's protective layer becomes weakened or damaged. A mucus-lined barrier protects the wall of your stomach from the acids that help digest your food. Weaknesses in the barrier allow your digestive juices to damage and inflame your stomach lining. A number of diseases and conditions can make your stomach's protective layer vulnerable to damage and increase your risk of gastritis.

Gastritis can occur suddenly or develop over weeks and months:

  • Acute gastritis is stomach inflammation that develops quickly and lasts for a short period of time.
  • Chronic gastritis develops gradually and may last for an extended period of time.
Apr. 09, 2011