Peptic ulcers are open sores that develop on the lining of the stomach or the upper part of the small intestine. They occur when the protective mucus layer is weakened, allowing stomach acid to damage the tissue. Common causes include infection with the bacterium Helicobacter pylori and the long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs). Symptoms of peptic ulcers can include burning stomach pain, bloating, and nausea. Treatment typically involves medications to reduce stomach acid and antibiotics if an H. pylori infection is present. Lifestyle changes, such as avoiding spicy foods and reducing stress, can also help manage symptoms.