What Is Gastritis?

Gastritis occurs when the gastric mucosa, the inner lining of the stomach, becomes inflamed.

Causes of gastritis

Gastritis has many causes, including infections, medications, autoimmune reactions (in which the body begins to attack its own tissues), and food hypersensitivities or allergies.

The most common infection of the stomach is caused by a bacterium called Helicobacter pylori (H. pylori). Infestation results from ingesting food or water contaminated with H. pylori and can result in a lifelong infection. In fact, an estimated 30 to 40 percent of Americans are infected with H. pylori. Infection irritates and inflames the stomach lining and leads to overproduction of gastric acid, which increases the risk of developing peptic ulcers (ulcers in the stomach or duodenum) and gastric cancer.

The medications that most often cause gastritis are nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin, ibuprofen (Advil, Motrin), and naproxen (Aleve, Naprosyn). NSAIDs interfere with protective substances in the stomach that prevent damage to the mucosal lining; these drugs also inhibit the body’s ability to stop bleeding.

The combination of NSAIDs and H. pylori is especially damaging to the gastric mucosa and may lead not only to gastritis but also to the development of erosions (superficial defects) and ulcerations (deep defects) in the mucosal lining of the stomach and duodenum.

Newer types of NSAIDs called COX-2 inhibitors were developed to reduce the risk of gastritis and stomach ulcers associated with traditional NSAIDs. However, not all studies have shown COX-2 inhibitors to be safer for the stomach than other NSAIDs. In fact, the only COX-2 inhibitor currently available, celecoxib (Celebrex), carries a “black box” warning on its label informing consumers of the potential for gastrointestinal side effects. Two other COX-2 inhibitors—rofecoxib (Vioxx) and valdecoxib (Bextra)—were taken off the market because they increase the risk of heart attacks and strokes.

Symptoms and diagnosis of gastritis

The symptoms of gastritis include indigestion (upset stomach) and abdominal pain, particularly after meals.

The best way to diagnose gastritis is with an upper endoscopy, in which a long, thin, flexible tube with a tiny light and video camera at its tip—an endoscope—is inserted through the throat and into the digestive tract. Through the camera, your doctor will look for changes in the gastric mucosa, such as swelling, redness and erosions. A definitive diagnosis is made by microscopic examination of a tissue sample removed during the endoscopy. The pathologist who examines the tissue will look for signs of inflammation, the presence of H. pylori or evidence of autoimmune gastritis. H. pylori infection can also be diagnosed by a blood test that detects antibodies to the bacterium, a breath test or a stool test.

Treatment of gastritis

H. pylori infection can be cured with drugs that suppress gastric acid production and oral antibiotics to eradicate the infection. If a medication you are taking is causing gastritis, your doctor may lower the dosage or switch you to another one. Your doctor may also recommend taking medication to decrease gastric acid production and protect the lining of the stomach.

Meet Our Writer

HealthAfter50 was published by the University of California, Berkeley, School of Public Health, providing up-to-date, evidence-based research and expert advice on the prevention, diagnosis, and treatment of a wide range of health conditions affecting adults in middle age and beyond. It was previously part of Remedy Health Media's network of digital and print publications, which also include HealthCentral; HIV/AIDS resources The Body and The Body Pro; the UC Berkeley Wellness Letter; and the Berkeley Wellness website. All content from HA50 merged into Healthcentral.com in 2018.