ON THIS PAGE: You will find out more about the factors that increase the chance of developing this type of cancer. To see other pages, use the menu on the side of your screen.
A risk factor is anything that increases a person’s chance of developing cancer. Although risk factors often influence the development of cancer, most do not directly cause cancer. Some people with several risk factors never develop cancer, while others with no known risk factors do. However, knowing your risk factors and talking about them with your doctor may help you make more informed lifestyle and health care choices.
The following factors may raise a person’s risk of developing stomach cancer:
- Age. Stomach cancer occurs most commonly in people older than 55. Most people diagnosed with stomach cancer are in their 60s and 70s.
- Gender. Men have twice the risk of developing stomach cancer, compared with women.
- Bacteria. A common bacterium called Helicobacter pylori, also called H. pylori, causes stomach inflammation and ulcers. It is also considered one of the primary causes of stomach cancer. Testing for H. pylori is available and an infection can be treated with antibiotics. Testing for H. pylori is recommended if you have had a first-degree relative, such as a parent, sibling, or child, who has been diagnosed with stomach cancer or with H. pylori infection. Other family members could have it as well, and the infection should be treated if found.
- Family history/genetics. People who have a parent, child, or sibling who has had stomach cancer are at increased risk. In addition, certain inherited genetic disorders, such as hereditary diffuse gastric cancer , Lynch syndrome , and familial adenomatous polyposis  (FAP) may increase the risk of stomach cancer. Learn more about genetics and cancer .
- Race/ethnicity. Stomach cancer is more common in black, Hispanic, and Asian people than in white people.
- Diet. Eating a diet high in salt has been linked to an increased risk of stomach cancer. This includes foods preserved by drying, smoking, salting, or pickling and foods high in added salt. Eating fresh fruits and vegetables may help lower the risk.
- Previous surgery or health conditions. People who have had stomach surgery or have one of the following conditions have a higher risk of stomach cancer: pernicious anemia or achlorhydria. Pernicious anemia is a severe decrease in red blood cells that occurs when the body does not have enough B12 usually because the stomach is not able to properly absorb the vitamin. Achlorhydria is a lack of hydrochloric acid in the gastric juices, which help digest food.
- Occupational exposure. Exposure to certain dusts and fumes may increase the risk of developing stomach cancer.
- Tobacco and alcohol. Tobacco use  and excessive alcohol consumption  may increase the risk of developing stomach cancer.
- Obesity. Excess body weight increases a man’s risk of developing stomach cancer. It is not clear whether obesity increases a woman’s risk of stomach cancer.
The next section in this guide is Symptoms and Signs  and it explains what body changes or medical problems this disease can cause. Or, use the menu on the side of your screen to choose another section to continue reading this guide.