What is Helicobacter pylori (H. pylori)?

Helicobacter pylori (H. pylori) 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 pain and 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 make an enzyme called urease. This enzyme makes your stomach acids less acidic. It also 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 cause the stomach to make more acid. Health experts don’t fully understand how.

H pylori can also lead to stomach cancer.

What causes H. pylori infection?

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

Who is at risk for H. pylori infection?

You may be at greater risk for H. pylori infection because of:

• Your age. Over half the people in the U.S. with the bacteria are older than age 50.

• Your race or ethnicity. Almost half of all African Americans have the bacteria. Out of the 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.

What are the symptoms of H. pylori?

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. The pain 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)

• Cause anemia because of bleeding

Other symptoms of an ulcer may include:

• Losing weight

• 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.

How is H. pylori diagnosed?

Your healthcare provider will look at your past health and give you a physical exam. You may also need to have tests, including:

• Blood tests. These check for infection-fighting cells (antibodies) that mean you have the bacteria.

• Stool culture. This test 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.

• Stool antigen test. This test takes a stool sample to check for the H. pylori 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. 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.

How is H. pylori treated?

Treatment will depend on your symptoms, age, and general health. It will also depend on how severe the condition is.

Your healthcare provider may have you take medicine that kills bacteria (antibiotics).

Other medicines may include:

• H-2 blockers. These are used to reduce the amount of acid in your stomach by blocking the hormone histamine. Histamine helps to make acid.

• Proton pump inhibitors.  These help to keep your stomach from making acid. They do this by stopping the stomach's acid pump from working.

• Stomach-lining protectors. These medicines protect your stomach lining from acid and help kill bacteria.

You may have to take multiple medicines at the same time to get rid of the H. pylori. Sometimes the medicine plan can be complicated, but it is important to follow instructions to get rid of the bacteria.

What are possible complications of H. pylori?

If you are infected with the bacteria, you can get a painful sore called a peptic ulcer. These sores form in your upper digestive tract.

A very bad ulcer can wear away your stomach lining. It can also cause problems, such as:

• Bleeding when a blood vessel is worn away

• A hole or perforation in your stomach wall

• Blockage when the ulcer is in a spot that blocks food from leaving your stomach

H. pylori can also lead to stomach cancer.

What can I do to prevent H. pylori?

Health experts don’t know for sure how the bacteria passes from person to person. But having good health habits (hygiene) can help keep you safe. These habits include:

• Washing your hands with soap and clean, running water. It is very important to do this after using the bathroom and before eating.

• Making sure all food you eat has been cleaned and cooked safely.

• Making sure that your drinking water is safe and clean.

Living with H. pylori

Once you know for sure that you have H. pylori, follow up with your healthcare provider. They will do some tests to make sure the bacteria has been removed.

When should I call my healthcare provider?

Call your healthcare provider if your symptoms get worse or you have new symptoms. Call right away if you have symptoms, such as bloody vomit, blood in your stools, or black, tarry-looking stools. Call your healthcare provider if you are losing weight without trying.

Key points about H. pylori

• H. pylori is a type of bacteria that infects your stomach.

• It attacks your stomach and the first part of your small intestine (duodenum). This can cause redness and swelling (inflammation).

• Many people with the bacteria won’t have any symptoms.

• It can cause open sores called peptic ulcers in your upper digestive tract.

• It can cause stomach cancer.

• It may be passed or spread from person to person by mouth, such as by kissing. It may also be passed by direct contact with vomit or stool.

• Having good health habits (hygiene) can help protect you.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

• Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your healthcare provider if you have questions, especially after office hours or on weekends.