Helicobacter Pylori Infection
(Peptic Ulcer Disease)

Helicobacter pylori (HEEL-ih-ko-bak-ter pie-LOR-eye) infection, the major cause of peptic ulcer disease, is a bacterial infection that can lead to inflammation and ulcers * in the lining of the stomach and the upper part of the small intestine *


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Digestive system



Peptic ulcer

Small intestine


What Is H. pylori Infection?

For years scientists and doctors thought that stomach and intestinal ulcers were caused by stress, eating spicy foods, or drinking too much alcohol. But in 1982 two Australian doctors, Barry Marshall and Robin Warren, discovered that H. pylori, a bacterium that lives in the lining of the stomach, can cause what is known as peptic ulcer disease. H. pylori infection is found in about 90 percent of people with ulcers in the duodenum (do-uh-DEE-num), the upper part of the small intestine. H. pylori infection is also responsible for most gastric (GAS-trik), or stomach, ulcers. Although H. pylori bacteria are responsible for most peptic ulcers, ulcers also can be caused by regularly taking certain medications, such as aspirin or ibuprofen; long-term smoking or alcohol use; infection with certain viruses; and, rarely, tumors in the pancreas or small intestine that lead to overproduction of stomach acid.

* ulcers are open sores on the skin or the lining of a hollow body organ, such as the stomach or intestine. They may or may not be painful.

* small intestine is the part of the intestines—the system of muscular tubes that food passes through during digestion—that directly receives the food when it passes through the stomach.

H. pylori infection also can cause gastritis (gah-STRY-tis), or inflammation of the lining of the stomach, in adults and children. Even though infection with H. pylori can cause disease, most people who have the bacteria in their stomach or intestines never experience any symptoms. In fact, the presence of H. pylori bacteria appears to lessen the risk that a person will get another serious disease, cancer of the esophagus * .

As early as the nineteenth century, people had seen particular bacteria among the cells of the mucous lining of the stomach, particularly around ulcers. No one had ever been able to isolate the organisms until Barry Marshall and Robin Warren accidentally left cultures in an incubator over the Easter weekend, thus extending the usual incubation period. It turned out that the Helicobacter bacteria grow much more slowly than other types of bacteria. Custom Medical Stock Photo, Inc.
As early as the nineteenth century, people had seen particular bacteria among the cells of the mucous lining of the stomach, particularly around ulcers. No one had ever been able to isolate the organisms until Barry Marshall and Robin Warren accidentally left cultures in an incubator over the Easter weekend, thus extending the usual incubation period. It turned out that the Helicobacter bacteria grow much more slowly than other types of bacteria.
Custom Medical Stock Photo, Inc.

How Common Is H. pylori Infection?

According to the U.S. Centers for Disease Control and Prevention (CDC), about two-thirds of the world's population is infected with H. pylori, but most people will never experience any symptoms. In the United States, H. pylori infection is more common among older adults, people from lower socioeconomic groups, and Hispanics and African Americans. Each year between 500,000 and 850,000 new cases of ulcer disease are diagnosed in the United States.

Is the Infection Contagious?

H. pylori infection may be contagious, but it is not known how it spreads. Some doctors suspect that the infection can be spread when an infected person passes the bacterium in feces (FEE-seez), or bowel movements. When another person comes into contact with the infected feces, whether by changing a diaper, cleaning a bathroom, or doing someone's laundry, he or she could become infected with the bacterium. Mouth-to-mouth contact also may contribute to the spread of H. pylori infection. Some research has found H. pylori bacteria in saliva, leading researchers to suggest that kissing is one way that the bacteria spread. In addition, coming into contact with food, water, or vomited material that contains H. pylori bacteria also may put a person at risk of infection.

* esophagus (eh-SAH-fuh-gus) is the soft tube that, with swallowing, carries food from the throat to the stomach.

What Are the Signs and Symptoms of
H. pylori Infection?

H. pylori infection can cause a variety of symptoms, but the most common one is abdominal pain. A person with peptic ulcer disease may feel a gnawing or burning pain below the ribs and above the navel. Abdominal pain from an ulcer usually occurs when the stomach is empty, typically several hours after eating or in the morning or evening hours. Eating food, drinking milk, or taking antacids may make the pain subside for a short while.

Other symptoms of peptic ulcer disease may include:

  • frequently feeling sick to the stomach (nausea, NAW-zee-uh)
  • loss of appetite
  • frequent burping
  • sudden, sharp abdominal pain
  • weight loss
  • vomiting
  • bloody or black stools

How Do Doctors Make the Diagnosis?

If a person has lasting abdominal pain or other symptoms of peptic ulcer disease, there are several methods a doctor can use to make a diagnosis. One of the most common ways to check for ulcers is with endoscopy (en-DOS-ko-pee). For this procedure, a person is given medication to relax and numb the throat. Then a doctor gently inserts an endoscope, a thin, flexible tube with a camera and light on the end, down the throat, through the esophagus, and into the stomach and intestines. The camera on the end of the endoscope allows the doctor to view the digestive system and take pictures of it. In addition, the doctor can perform a biopsy, removing a small amount of tissue for study. The biopsy tissue can be sent to a laboratory for further testing and to check for evidence of H. pylori infection.

A person suspected of having H. pylori infection also might undergo a breath test. During a breath test, a person drinks a liquid containing a carbon marker known as carbon-13 ( 13 C). The person then provides a breath sample by blowing up a balloon or blowing bubbles. The sample is checked for the presence of the 13 C marker. If the person has H. pylori infection, there will be traces of 13 C present in the carbon dioxide gas molecules of the person's breath. Although it is less helpful than endoscopy, another test that may be used to check for ulcers is an upper gastrointestinal * series, a set of X rays of the gastrointestinal system. A person taking the test first drinks a white, chalky liquid called barium, which helps highlight the ulcer and makes it visible on the X ray. A person's blood also can be checked for the presence of antibodies * to H. pylori, indicating infection.

How Is H. pylori Infection Treated?

Years ago people who had ulcers were given medication to lessen the production of stomach acid. This treatment minimized pain by allowing the ulcer to heal, but it did not treat the infection causing the inflammation. It was not uncommon for ulcers to return after this treatment was stopped.

Today, peptic ulcer disease usually is treated for 2 weeks with a combination of two or three antibiotic medicines that kill H. pylori bacteria, in addition to about a month of other prescribed medications that limit acid production as the ulcer heals. Treatment with antibiotics greatly lessens the chance that peptic ulcers will recur. After treatment is completed, tests sometimes are done to check that H. pylori infection has been eliminated from the body. Together with medication, eating regular small meals to prevent having an empty stomach for long periods of time may help decrease the pain associated with ulcers. A doctor also may advise avoiding ibuprofen or other medications that can cause stomach irritation.

How Ulcers Form

How exactly does H. pylori cause ulcers? Doctors think that H. pylori bacteria first weaken the protective coating of the stomach and duodenum. Then the acid in the stomach that assists in digestion can irritate the sensitive tissues of the digestive system. Finally, acid and bacteria from the stomach come in direct contact with the digestive system lining, resulting in the sores called ulcers.

* gastrointestinal (gas-tro-in-TES-tih-nuhl) means having to do with the organs of the digestive system, the system that processes food. It includes the mouth, esophagus, stomach, intestines, colon, and rectum and other organs involved in digestion, including the liver and pancreas.

* antibodies (AN-tih-bah-deez) are protein molecules produced by the body's immune system to help fight specific infections caused by microorganisms, such as bacteria and viruses.

With the recommended treatment, ulcers can take a few weeks to heal. Without antibiotic treatment to get rid of the bacteria, the infection can return, and the painful ulcers may not go away. Sometimes antibiotic treatment needs to be repeated over the course of a few months to eliminate the infection.

Are There Complications of H. pylori Infection?

A person who has untreated H. pylori infection has an increased risk of developing stomach cancer later in life. Long-term loss of blood from the gastrointestinal tract due to ulcers can cause anemia * . Severe untreated ulcers can lead to a perforation, or a hole, when the sore erodes all the way through the lining of the stomach or intestine. Perforations can cause sudden severe bleeding that, in some cases, can be fatal.

Can H. pylori Infection Be Prevented?

Although doctors are not sure how H. pylori is spread, they believe that washing the hands often with warm, soapy water, especially after using the bathroom and before eating, may help prevent the spread of the infection.

Because water and food can be contaminated with H. pylori, it is important to ensure that any water used for drinking or preparation of food comes from a safe source. It also is advisable to heat foods to proper temperatures and to wash utensils and dishes in hot, soapy water.

Because smoking and heavy drinking of alcoholic beverages have been associated with the development of peptic ulcers, avoiding these habits may help prevent the disease.

At present, there is no vaccine against H. pylori infection.

* anemia (uh-NEE-me-uh) is a blood condition in which there is a decreased amount of oxygen-carrying hemoglobin in the blood and, usually, fewer than normal numbers of red blood cells.

See also
Intestinal Infections



The Helicobacter Foundation was founded by Dr. Barry Marshall in 1994 and provides information about the diagnosis and treatment of H. pylori infection at its website.

U.S. Centers for Disease Control and Prevention (CDC), 1600 Clifton Road, Atlanta, GA 30333. The CDC posts English and Spanish fact sheets about H. pylori and peptic ulcers at its website.
Telephone 800-311-3435

U.S. National Digestive Diseases Information Clearinghouse, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, 2 Information Way, Bethesda, MD 20892. The NIDDK publishes brochures and posts fact sheets about H. pylori and peptic ulcers at its website.

User Contributions:

Debbie Williams
Report this comment as inappropriate
Mar 24, 2018 @ 3:03 am
I was exsposed to black mold from 1997 through 2005 felt better i had a Ultra Sound in 2001 due to a work injury where i was told i should stop drinking my liver looked like i was a heavy drinker. I found that odd, i drank rarely.
I moved in 2012 still feeling ok.
I then moved back to where i had lived in 1997 through 2005. I began to get ill after 6 months so bad i couldnt walk to pee at night. My boyfriend had to take me. I lived there sicker and sicker til Jan 2018. On Feb 2018 i was informed i may have pancreatic cancer could this be caused my black mold posioning?

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