The main causes of gastric ulcers are Helicobacter pylori bacteria, regular pain reliever use, bisphosphonate use and potassium supplement use, as reported by Mayo Clinic. H. pylori infection causes most ulcers, according to WebMD.
H. pylori bacteria live in the protective mucous layer that coats the stomach and small intestine, according to Mayo Clinic. H. pylori usually causes no problems, but it can cause inflammation in the stomach's lining, leading to ulceration. The way H. pylori spreads is not clearly understood, but the bacteria may spread from close contact between people. H. pylori may also spread through food and water.
Both prescription and over-the-counter pain medications can irritate the lining of the stomach, according to Mayo Clinic. These medications include aspirin, ibuprofen, naproxen and ketoprofen. People who take pain medications regularly are more at risk for ulcers. Potassium and bisphosphonate use also increases the risk for ulcers. Bisphosphonates are medications used to treat osteoporosis.
Smoking and drinking alcohol also increases the chance of developing gastric ulcers, as reported by Mayo Clinic. Smoking enhances the risk in people who are infected with H. pylori. Alcohol irritates and erodes the lining of the stomach as well as increases the amount of stomach acid produced.