A gastric ulcer is a type of peptic ulcer that forms in the lining of the stomach. It is a sore or erosion in the stomach's lining that can cause pain, discomfort, and other symptoms. Gastric ulcers are usually caused by a bacterial infection with Helicobacter pylori (H. pylori) or long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs). Symptoms may include burning or gnawing pain in the abdomen, nausea, vomiting, loss of appetite, and weight loss. Treatment typically involves a combination of antibiotics to eradicate the H. pylori infection and acid-suppressing medications to reduce stomach acid production and promote healing of the ulcer. In severe cases, surgery may be necessary to remove the ulcer or repair any damage it has caused.