Gastritis Gastritis Gastritis is inflammation of the stomach lining. The inflammation can be caused by many factors, including infection, stress resulting from severe illness, injury, certain drugs, and disorders... read more 
and peptic ulcer disease Peptic Ulcer Disease A peptic ulcer is a round or oval sore where the lining of the stomach or duodenum has been eaten away by stomach acid and digestive juices. Peptic ulcers can result from Helicobacter pylori... read more 
involve damage to the lining of the stomach or duodenum (the first segment of the small intestine). These disorders are usually caused by
Stomach acid (hydrochloric acid)
Digestive enzymes (especially pepsin)
Use of certain drugs, such as nonsteroidal anti-inflammatory drugs Nonsteroidal Anti-Inflammatory Drugs Pain relievers (analgesics) are the main drugs used to treat pain. Doctors choose a pain reliever based on the type and duration of pain and on the drug's likely benefits and risks. Most pain... read more (NSAIDs)
In Zollinger-Ellison syndrome Gastrinoma A gastrinoma is a tumor usually in the pancreas or duodenum (the first segment of the small intestine) that produces excessive levels of the hormone gastrin, which stimulates the stomach to... read more , a rare tumor that usually occurs in the duodenum, pancreas, or adjacent structures, produces a hormone called gastrin that causes the stomach to produce too much acid.
Usually the lining of the stomach Stomach The stomach is a large, bean-shaped, hollow muscular organ consisting of three regions: Cardia Body (fundus) Antrum (See also Overview of the Digestive System.) read more is protected by certain defense mechanisms. The cells that line the stomach secrete mucus and bicarbonate. The mucus coats the inside of the stomach to protect it from being damaged by acid and digestive enzymes. The bicarbonate within and under the mucus helps neutralize stomach acid. When these defense mechanisms are disrupted, for example, by the bacterium Helicobacter pylori or aspirin, people may develop gastritis Gastritis Gastritis is inflammation of the stomach lining. The inflammation can be caused by many factors, including infection, stress resulting from severe illness, injury, certain drugs, and disorders... read more or peptic ulcer disease Peptic Ulcer Disease A peptic ulcer is a round or oval sore where the lining of the stomach or duodenum has been eaten away by stomach acid and digestive juices. Peptic ulcers can result from Helicobacter pylori... read more . There are many treatment options available (see Drug Treatment of Stomach Acid Drug Treatment of Stomach Acid Stomach acid plays a role in a number of disorders of the stomach, including peptic ulcer, gastritis, and gastroesophageal reflux disease (GERD). Although the amount of acid present in the stomach... read more ).
