The cause of gastritis is an imbalance between the stomach acid and the mucous membrane protecting the stomach. When the acid gets the upper hand, it can damage the mucous membrane, preventing it from properly forming mucus to protect itself. This can then develop into a stomach ulcer in the further course and in severe cases the stomach wall can be destroyed by the stomach acid to such an extent that a hole in the stomach and inflammation of the abdomen occur.
The most common reasons for gastritis are smoking, alcohol consumption, an unhealthy diet, psychological stress and a bacterium that lives in the stomach of almost every second person in Germany. This bacterium, Helicobacter pylori triggers inflammation of the stomach lining in some people, but can be killed with medication. Medications can also trigger gastritis, especially over-the-counter painkillers such as ibuprofen are often responsible for this, which is why prolonged use should only be done after consulting a doctor.