Health A-Z

Medical Content Created by the Faculty of the
Harvard Medical School

Gastritis

What Is It?

Gastritis is an inflammation of the stomach lining. The lining of the stomach often looks red, irritated and swollen, and it may have raw areas that can bleed.

Many different illnesses and irritants — acting either alone or in combination — can trigger the inflammation of gastritis. Some of the most common triggers include:

• Infection with Helicobacter pylori (H. pylori) bacteria — In addition to causing gastritis, H. pylori infections have been linked to the development of stomach cancer and peptic ulcer disease, open sores inside the stomach or part of the small intestine. Although doctors are not sure how people become infected with H. pylori, they suspect the bacteria are spread through contaminated food, water, saliva or digestive fluids. In the United States, the number of people infected with H. pylori increases with age. About 20% of Americans under age 40 have the bacteria, while it infects about 50% of people over age 60. Many people infected with H. pylori never complain of digestive symptoms. Doctors don't understand why people respond differently.

• Viral infections — Brief bouts of gastritis are common during short-term viral infections.

• Irritants — Chemical and environmental irritants can damage the stomach lining and cause gastritis. Common irritants include alcohol; cigarette smoke; corticosteroids and certain other prescription medications; and aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Advil, Motrin and others) and naproxen (Aleve, Naprosyn and others).

In the United States, gastritis accounts for approximately 2 million visits to doctors' offices each year. Although gastritis can occur in people of all ages and backgrounds, it is especially common in:

• People over age 60

• People who drink too much alcohol

• Smokers

• People who take corticosteroids or other prescription medications that can cause gastritis

• People who routinely use aspirin or NSAIDs, especially at high doses