Overview of Gastritis By Nimish Vakil, MD, University of Wisconsin School of Medicine and Public Health Reviewed / Revised Mar 2023 View Patient Education Topic Resources Acute Gastritis Chronic Gastritis Gastritis is inflammation of the gastric mucosa caused by any of several conditions, including infection (Helicobacter pylori), drugs (nonsteroidal anti-inflammatory drugs, alcohol), stress, and autoimmune phenomena (atrophic gastritis).