Diabetes, also known as diabetes mellitus

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 (see dyspepsia).^[1] Other possible symptoms include nausea and vomiting, bloating, loss of appetite and heartburn.^[1][2] Complications may include stomach 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 nonsteroidal anti-inflammatory drugs (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.^]
Prevention is by avoiding things that cause the disease. Treatment includes medications such as antacids, H2 blockers, or proton pump inhibitors. During an acute attack drinking viscous lidocaine may help.^[7] If gastritis is due to NSAIDs these may be stopped.^[1] If H. pylori is present it may be treated with a combination of antibiotics such as amoxicillin and clarithromycin.^[1] For those with pernicious anemia, vitamin B12 supplements are recommended either by mouth or by injection.^[3] People are usually advised to avoid foods that bother them.^[8]
Gastritis is believed to affect about half of people worldwide.^[4] In 2013 there were approximately 90 million new cases of the condition.^[9] As people get older the disease becomes more common.^[4] It, along with a similar condition in the first part of the intestines known as duodenitis, resulted in 50,000 deaths in 2015.^[5] H. pylori was first discovered in 1981 by Barry Marshall and Robin Warren.^[10]
Signs and symptoms

A peptic ulcer may accompany gastritis. Endoscopic image.
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: