What Will Happen If H Pylori Goes Untreated?

Medically Reviewed on 2/28/2022
helicobacter pylori
If left untreated H pylori infection can cause abdominal symptoms, as well as lead to the following complications.

If left untreated H pylori infection initially can cause abdominal symptoms, such as nausea, vomiting, pain, and diarrhea among others.

Long-standing untreated infection can lead to the following complications:

  • Inflammation of the stomach lining. H pylori infection can irritate the stomach, causing inflammation (gastritis).
  • Ulcers. H pylori damage the protective mucosal lining of the stomach and small intestine.
    • This can allow stomach acid to create a break in the protective lining (ulcer). 
    • About 10 percent of people with H pylori infection will develop an ulcer.
    • Data from the developed world have shown that the lifetime risk of developing peptic ulcer disease (PUD) was 3 to 10 times higher in H pylori-positive subjects.
  • Stomach cancer. H pylori infection has a strong association with certain types of stomach cancer. Data suggests that H pylori increase the risk of stomach cancer by six times.

H pylori is a bacterium that resides in the human stomach. It is a common cause of peptic ulcers. More than 50 percent of the world’s population is infected with H pylori.

Most people never experience any symptoms due to H pylori infection and, thus, do not realize that they are harboring the bacterium in their stomach. The doctor will probably test for the infection only if there are signs and symptoms of a peptic ulcer.

H pylori infection can be treated with antibiotics and is completely curable.

What causes H pylori infection?

H pylori is a bacterium that is present in the stomach and does not cause any symptoms.

H pylori infection is caused most commonly by consuming food or water or any liquid contaminated with the fecal matter containing the H pylori bacteria. It can be transmitted through direct contact with the saliva or vomit of the infected person. It is still unclear why some people with H pylori develop the symptoms while others do not.

Some people with H pylori infection develop a variety of digestive problems, such as persistent inflammation of the stomach (chronic gastritis), or inflammation of the duodenum (duodenitis), which can transform into complications, such as stomach ulcers and cancer.

The changes in stomach cell lining leading to inflammation and cancer occur in the following steps:

  • The bacteria infects the protective tissue (mucosa) that lines the stomach.
  • Certain enzymes and toxins are released.
  • The immune system gets activated.
  • Together, these factors may injure the cells of the digestive tract (stomach or duodenum) that result in digestive system disorders.
  • The development of stomach cancer is a multistep process progressing from chronic gastritis, degeneration or shrinkage of gastric glands (glandular atrophy), replacement of gastric cell lining with intestinal cell lining (intestinal metaplasia) to the stage of development of abnormal cells in the stomach tissue (dysplasia), proceeding to a stage of cancer.


Bowel regularity means a bowel movement every day. See Answer

Who is at risk for H pylori infection?

In developing countries, you have greater chances of getting an H pylori infection during your childhood. However, in the United States and other developed countries, H pylori infections are more common during adult age.

You are at risk of H pylori infection if you:

  • Live in a crowded house
  • Live in places without a reliable supply of clean water
  • Live in a developing country (lack of sanitation, lower socioeconomic status, unfiltered water)
  • Live with someone who has an H pylori infection
  • Eat restaurant food
  • Smoke
  • Have a family history of peptic ulcer
Consumption of chili peppers and concurrent parasite infestation is protective against H pylori.

8 symptoms of H pylori infection

H pylori infection can give rise to one or more of the following symptoms:

  1. Abdominal pain or discomfort (upper abdomen)
  2. Nausea
  3. Vomiting
  4. Bloating
  5. Heartburn (burning sensation in the chest)
  6. Diarrhea
  7. Morning hunger
  8. Halitosis (bad breath)

Which tests are used to diagnose H pylori infection?

The most common tests used to diagnose H pylori are:

  • Urea breath tests: After you drink a specialized solution, you are then asked to blow through a straw into a glass tube. Your breath will then be tested for the presence of carbon molecules, which make the test positive (H pylori infection is present).
  • Stool tests: Stool antigen tests detect H pylori proteins in the stool.
  • Blood tests: Specific antibody tests done using the blood can help detect active or old infection.

How is H pylori infection treated?

Successful treatment of H pylori can help the ulcer heal, prevent recurrence of ulcers, and reduce the risk of ulcer complications (such as bleeding and cancer).

The most effective treatment for H pylori involves medications to be taken for two weeks and is called triple therapy, which includes the following:

  1. Proton pump inhibitor, such as omeprazole, pantoprazole, Prevacid (lansoprazole), and rabeprazole
  2. Bismuth subsalicylate
  3. Two different antibiotics (metronidazole and tetracycline or metronidazole and amoxicillin)

The best treatment regimens may vary with your antibiotic resistance.

It is important to take the entire course of all medications to get maximum results from H pylori treatment.

After completing H pylori treatment, repeat testing is usually performed to ensure that the bacterium has been eradicated. This is typically done with a breath or stool test on follow-up. 

Blood tests are not recommended on follow-ups. The antibody detected by the blood test often remains in the blood for four or more months after treatment even after the bacterium has been eliminated.

Medically Reviewed on 2/28/2022
Image Source: iStock Images

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Yamagata H, Kiyohara Y, Aoyagi K, et al. Impact of Helicobacter pylori Infection on Gastric Cancer Incidence in a General Japanese Population: The Hisayama Study. Arch Intern Med. 2000;160(13):1962–1968. doi:10.1001/archinte.160.13.1962