• Definition

    Gastritis occurs when the lining of the stomach becomes inflamed or swollen.

    Gastritis can last for only a short time (acute gastritis), or linger for months to years (chronic gastritis).

    Causes, incidence, and risk factors

    The most common causes of gastritis are:

    • Certain medications, such as aspirin, ibuprofen, or naproxen, when taken over a longer period of time
    • Drinking too much alcohol
    • Infection of the stomach with a bacteria called Helicobacter pylori

    Less common causes are:

    • Autoimmune disorders (such as pernicious anemia)
    • Backflow of bile into the stomach (bile reflux)
    • Cocaine abuse
    • Eating or drinking caustic or corrosive substances (such as poisons)
    • Extreme stress
    • Viral infection, such as cytomegalovirus and herpes simplex virus, especially in people with a weak immune system

    Trauma or a severe, sudden illness such as major surgery, kidney failure, or being placed on a breathing machine may cause gastritis.