The most common causes that gastritis are;
1. the consumption and abuse of alcohol
2. unhealthy eating habits
3. high consumption of dairy products
4. consuming too much fat and low fiber
5. caffeine
6. spicy foods with many spices
7. smoking
8. stress
9. Abuse of analgesics.
In other cases it may also be caused by pernicious Anemia (it is not an iron deficiency anemia, but is due to the fact that the body does not assimilate vitamin B12 well) and gastritis can also be caused by an infection by the bacterium Helicobacter pylori.