What causes stomach cancer?

A long-lasting Helicobacter pylori infection can inflame and damage the stomach lining. Over time, persistent inflammation may lead to changes in the cells and the way the lining is maintained. Some people develop a higher risk through inherited gene changes or a family history, while others have no single identifiable cause.

Risk can also be shaped by chronic stomach inflammation, certain stomach polyps, smoking, dietary patterns, and previous stomach surgery. These factors do not mean that cancer will occur, and many people with one factor never develop it. Testing and medical history help clarify which issues matter for an individual.

Discuss persistent indigestion, upper abdominal discomfort, nausea, early fullness, unexplained weight loss, or difficulty swallowing with a clinician. They may review medicines and family history, test for Helicobacter pylori, or recommend an endoscopy if symptoms or risk factors warrant a closer look. Do not stop prescribed treatment without advice.

Arrange prompt assessment for ongoing stomach symptoms, vomiting, black stools, anemia, or loss of appetite that does not settle. Seek urgent care for vomiting blood, black tar-like stools with weakness or dizziness, severe abdominal pain, or inability to keep fluids down. These symptoms can have causes other than cancer, but bleeding and dehydration need rapid attention.

Ask whether Helicobacter pylori testing is appropriate, whether your family history suggests inherited risk, and which symptoms should trigger an endoscopy. You can also ask how test results would change follow-up and whether a stomach medicine could affect testing.