Helicobacter pylori (H.pylori)


H. pylori (Helicobacter pylori, pronounced Hel-ee-koh-BAK-ter Pie-LORE-ee) is a type of bacteria that infects your stomach. It can damage the tissue in your stomach and the first part of your small intestine (the duodenum). This can cause redness and soreness (inflammation). In some cases it can also cause painful sores called peptic ulcers in your upper digestive tract.

H. pylori is common. Many people have it. Most people who have it won’t get ulcers or show any symptoms. But it is a main cause of ulcers. H. pylori attacks the lining that protects your stomach. The bacteria makes an enzyme called urease. This enzyme makes your stomach acids less acidic (neutralizes them). This weakens your stomach’s lining. Your stomach cells then have greater risk of being hurt by acid and pepsin, strong digestive fluids. That can lead to sores or ulcers in your stomach or duodenum.

The H. pylori bacteria can also stick to stomach cells. Your stomach can’t protect itself very well. The area gets red and swollen (inflamed). H. pylori can also get the stomach to make more acid. Health experts don’t fully understand how.


Health experts don’t know for sure how H. pylori infection is spread. They believe the germs can be passed from person to person by mouth, such as by kissing. It may also be passed by having contact with vomit or stool. This may happen if you:

  • Eat food that was not cleaned or cooked in a safe way
  • Drink water that is infected with the bacteria

Risk factors:

You may be at greater risk for H. pylori infection because of:
Age: Over half the people in the U.S. with the bacteria are over 50 years old.
Race or ethnicity: Almost half of all African Americans have the bacteria. For people who come to the U.S. from developing countries, at least 50% of Latinos and 50% of people from Eastern Europe have H. pylori.
Most people first get the bacteria when they are children, but adults can get it too.

Sign and symptoms:

Most people have the bacteria for years without knowing it because they don’t have any symptoms. Experts don’t know why. You may have redness and swelling (inflammation) in your stomach lining. This is called gastritis.

You may get sores or peptic ulcers in your stomach or the first part of your small intestine (duodenum). Ulcer symptoms may include belly or abdominal pain, which can:

  • Be a dull pain that doesn’t go away.
  • Happen 2 to 3 hours after you eat.
  • Come and go for several days or weeks.
  • Happen in the middle of the night when your stomach is empty.
  • Go away when you eat or take medicines that reduce your stomach acid level (antacids).

Other symptoms of an ulcer may include:

  • Weight loss
  • Not feeling hungry
  • Swelling or bloating
  • Burping
  • Having an upset stomach or nausea
  • Vomiting

The symptoms of ulcers may look like other health problems. Always see your healthcare provider to be sure.


Your healthcare provider will look at your past health and give you a physical exam. He or she may also use other tests, including:
Blood tests: These check for infection-fighting cells (antibodies) that mean you have the bacteria.
Stool culture: This looks for any abnormal bacteria in your digestive tract that may cause diarrhea and other problems. A small stool sample is collected and sent to a lab. In 2 or 3 days, the test will show if you have any abnormal bacteria.
Breath tests: These can check if there is any carbon after you swallow a urea pill that has carbon molecules. If carbon is found that means that H. pylori has made the enzyme urease. This enzyme makes your stomach acids less acidic (neutralizes them). It weakens your stomach’s mucous lining.
Upper endoscopy, also called EGD (esophagogastroduodenoscopy): This test looks at the lining of your food pipe (esophagus), stomach, and duodenum (the first part of your small intestine). It uses a thin, lighted tube or endoscope. The tube has a camera at one end. The tube is put into your mouth and throat. Then it goes down into your esophagus, stomach, and duodenum. Your healthcare provider can see the inside of these organs. A small tissue sample (biopsy) is taken if needed. The tissue sample can show if you have the enzyme urease. It can also check the bacteria that is there.