Gastritis can develop whenever the stomach's protective layer becomes weakened or damaged. A mucus-lined barrier protects the walls of your stomach from the acids that help digest your food. Weakness would allow acids to damage your stomach.
The following can cause gastritis:
- Bacterial infection
- Bile reflux disease
- Excessive alcohol use
- Overuse of pain relievers
- Stress (which causes 99.9% of everything)