Gastritis Risk Factors and Causes
Risk factors for gastritis include the following:
- Alcohol use
- Bacterial infection (e.g., Helicobacter pylori)
- Certain medications
- Chemotherapy drugs (used to destroy cancer cells)
- Iron and potassium supplements
- Nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., ibuprofen, naproxen)
- Erosion or thinning of the stomach lining (e.g., due to age)
- High levels of stress
The most common cause for gastritis is infection with Helicobacter pylori (H. pylori) bacteria. These small, corkscrew-shaped bacteria grow in the protective mucous layer of the stomach, where they are less exposed to strong stomach acids. Over time, H. pylori infection leads to an inflammatory response and irritation of the stomach lining.
Infection with H. pylori increases with age—by age 60, almost 50% of people are infected. Some people do not experience symptoms, but most people infected with H. pylori develop gastritis and/or peptic ulcers. People who have long-term H. pylori infections also are at increased risk for developing stomach cancer (also called gastric cancer).
H. pylori infection is diagnosed using a blood, breath, or stool test. If test results are positive, treatment involves antibiotics (usually amoxicillin and clarithromycin) and a proton pump inhibitor (medication that reduces the production of stomach acid; e.g., Prilosec®, Nexium®, Prevacid®) for a period of 7-14 days. Follow-up testing is done to make sure the treatment is successful.
If left untreated, gastritis due to H. pylori recurs in 60-80% of cases within one year. Following treatment, recurrence develops in less than 20% of cases.
Other factors that can contribute to gastritis include the following:
- Autoimmune disorders (e.g., pernicious anemia [vitamin B12 deficiency])
- Chemotherapy and/or radiation therapy (used to treat cancer)
- Chronic bile reflux (condition in which a substance produced in the liver that aids in digestion [bile] flows from the small intestine into the stomach and esophagus)
- Chronic vomiting (e.g., during chemotherapy)
- Crohn's disease
- Eating or drinking corrosive objects or substances (e.g., poisons)
- Infections due to tuberculosis (TB), syphilis, viruses, fungi (e.g., yeast), parasites
- Post-surgery inflammation after partial gastrectomy (removal of part of the stomach)
- Ménétrièr’s disease (characterized by excessive folds in the stomach lining)