What causes Gastritis?

Causes of gastritis include:

• Drugs (such as aspirin and other nonsteroidal anti-inflammatory medications [NSAIDs], as well as steroid drugs)
• Alcohol
• Smoking
• Severe illness, which can occur from:
  • Surgery
  • Burns
  • Liver or kidney disease
  • Shock
  • Respiratory failure
  • Head injury
  • Sepsis
• Viral infection (for example, herpes or cytomegalovirus )
• Bacterial infection, such as Helicobacter pylori
• Fungal infection
• Injury to the blood vessels that bring blood to the stomach
• Excess production of stomach acid
• Reflux of bile into the stomach, especially after surgery of the bile system
• Crohn's disease
• Atrophy of the lining of the stomach (atrophic gastritis), usually associated with older age
• Pernicious anemia (causes autoimmune gastritis)
• Syphilis
• Sarcoidosis
• Radiation treatment
• Swallowing caustic substances