Gastritis is inflammation of the lining of the stomach.[1] It may occur as a short episode or may be of a long duration.[1] There may be no symptoms but, when symptoms are present, the most common is upper abdominal pain.[1] Other possible symptoms include nausea and vomiting, bloating, loss of appetite and heartburn.[1][2] Complications may include bleeding, stomach ulcers, and stomach tumors.[1] When due to autoimmune problems, low red blood cells due to not enough vitamin B12 may occur, a condition known as pernicious anemia.[3]

Common causes include infection with Helicobacter pylori and use of NSAIDs.[1] Less common causes include alcohol, smoking, cocaine, severe illness, autoimmune problems, radiation therapy and Crohn's disease.[1][6] Endoscopy, a type of X-ray known as an upper gastrointestinal series, blood tests, and stool tests may help with diagnosis.[1] The symptoms of gastritis may be a presentation of a myocardial infarction.[2] Other conditions with similar symptoms include inflammation of the pancreas, gallbladder problems, and peptic ulcer disease.[2]

Many people with gastritis experience no symptoms at all. However, upper central abdominal pain is the most common symptom; the pain may be dull, vague, burning, aching, gnawing, sore, or sharp.[11] Pain is usually located in the upper central portion of the abdomen,[12] but it may occur anywhere from the upper left portion of the abdomen around to the back.

Other signs and symptoms may include the following:

Nausea

Vomiting (if present, may be clear, green or yellow, blood-streaked, or completely bloody, depending on the severity of the stomach inflammation)

Belching (if present, usually does not relieve the pain much)

Bloating

Early satiety[11]

Loss of appetite

Unexplained weight loss