Gastritis is a group of diseases that cause inflammation of the lining of the stomach. Acute gastritis (occurs suddenly) and chronic gastritis (develops slowly). The inflammation of the stomach lining is most frequently caused by a bacterium called H. pylori. Gastritis can vary greatly from mild gastritis to severe gastritis.
Gastritis can be caused by irritation due to excessive alcohol use, chronic vomiting, stress, or the use of certain medications such as aspirin or other anti-inflammatory drugs. It may also be caused by any of the following:
- Helicobacter pylori (H. pylori): A bacteria that lives in the mucous lining of the stomach; without treatment, the infection can lead to ulcers, and in some people, stomach cancer.
- Pernicious anemia: A form of anemia that occurs when the stomach lacks a naturally occurring substance needed to properly absorb and digest vitamin B12
- Bile reflux: A backflow of bile into the stomach from the bile tract (that connects to the liver and gallbladder)
- Infections caused by bacteria and viruses
The most common causes of gastritis are:
- Certain medicines, such as aspirin, ibuprofen, or naproxen
- Heavy alcohol drinking
- Infection of the stomach with a bacteria called Helicobacter pyloriLess common causes are:
- Autoimmune disorders (such as pernicious anemia)
- Backflow of bile into the stomach (bile reflux)
- Cocaine abuse
- Eating or drinking caustic or corrosive substances (such as poisons)
- Extreme stress
- Viral infection, such as cytomegalovirus and herpes simplex virus (more often occurs in people with a weak immune system)