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What Is H. Pylori Infection — Causes, Symptoms, Tests, & Treatment
Updated on March 23, 2023
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What Is H. Pylori Infection — Causes, Symptoms, Tests, & Treatment
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Helicobacter pylori (H. pylori) is a spiral-shaped bacteria that causes Helicobacter pylori infection. It usually penetrates your stomach lining or the upper part of your small intestine.

H. Pylori infection is common. Almost half of the world’s population has it in their bodies. However, most people don’t get sick or develop symptoms.

If you show signs of a stomach ulcer, your doctor may ask you to take an H. pylori test. H. Pylori infection is the leading cause of painful sores in the stomach lining.1

What Is H. Pylori Infection — Causes, Symptoms, Tests, & Treatment 2

What Causes H. Pylori Infections?

Food, water, or utensils contaminated with the H. Pylori bacteria cause H. Pylori infection. It typically happens in developing countries or communities with insufficient clean water or proper sewage systems.

Most H. pylori infection occurs in childhood. After the initial infection, they multiply in the mucus layer of your digestive tract.2

The bacteria thrive in your gut by releasing urease. The enzyme neutralizes the acids in your stomach and weakens its lining. 

In turn, the cells in your intestines become susceptible to digestive acids. As the population of H. pylori increases, your stomach is at increased risk of developing sores and inflammation. 


H. Pylori infection is caused by the H. Pylori bacteria. It commonly happens, especially in countries or communities that lack clean water or proper sewage system. Most cases of H. Pylori infection occur in childhood.

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How Is H. Pylori Spread?

H. pylori is often found in saliva, teeth plaque, and stool. 

Health experts believe that it’s possible to spread them through direct contact. Kissing and sharing unclean utensils can pass the bacteria from one person to another. 

However, contaminated food or water can also spread H. pylori bacteria.3 Contamination usually happens when you don’t wash your hands properly before eating or cooking.

Who Is At Risk For H. Pylori Infections?

H. pylori is often acquired at a young age. But only 20% of infections in children show symptoms.4

People with the following living conditions are at a higher risk of getting the infection:

  • Living with many people in a cramped home
  • Lack of a clean and stable supply of water for drinking
  • Unsanitary food preparation
  • Living with a person infected with H. pylori

Besides the environment, lifestyle and diet are also risk factors for H. pylori infection. Studies show that people with these habits have an increased risk of being infected:5

  • Dining at restaurants
  • Eating fast food or takeout
  • Consumption of meat
  • Drinking unfiltered water
  • Smoking

Symptoms of H. Pylori Infection

Not everyone infected with H. pylori shows symptoms. Healthcare experts still can’t explain why this is. People who do show symptoms will likely have signs of gastritis or peptic ulcer disease.

Gastritis is the inflammation of the stomach lining. Peptic ulcers are painful sores in the upper part of your small intestine.

Here are signs that you may have an H. pylori infection:

  • Dull or burning pain in your abdomen
  • Stomach ache that worsens on an empty stomach
  • Nausea or vomiting
  • Lack of appetite
  • Frequent burping
  • Bloating
  • Sudden weight loss

These symptoms, especially abdominal pain, may come and go for weeks. They usually disappear when you take antacids or medications that reduce the acidity of your gut.

However, if you have severe stomach pains, dark or bloody stools, or vomit that looks like coffee grounds, you must seek medical help immediately.

Health complications linked to H. Pylori Infection

When left untreated, H. Pylori infection may become chronic or long-term. It can lead to different health complications, including:

  • Peptic ulcers — H. Pylori can weaken the protective lining in your stomach and small intestine. When this happens, stomach acid can create open sores or ulcers, like gastric ulcers or duodenal ulcers
  • Gastritis — H. Pylori can irritate the stomach lining, causing swelling. If the inflammation becomes persistent, you may develop chronic gastritis
  • Stomach cancer — H. Pylori infection causes chronic inflammation in the stomach. It increases your risk of developing stomach cancer, like gastric cancer


The signs of an H. Pylori infection include stomach pains, nausea, vomiting, frequent burping, bloating, and sudden weight loss. Untreated H. Pylori infection may become long-term and lead to health problems like peptic ulcers, gastritis, and stomach cancer.

How to Test for H. Pylori Bacteria

The signs of an H. pylori infection may be similar to other health problems. The doctor might perform a physical exam and check your medical history to confirm your diagnosis.

Your healthcare provider may also ask you to take tests to help them identify the cause of your symptoms.

Blood Test

A blood test looks for antibodies or cells that fight disease-causing bacteria. It can show if you have an infection in your body.

Urea Breath Test

During H. Pylori breath tests, you’ll need to breathe into a bag twice. The first sample will serve as the baseline. The second sample will determine the presence of an infection.

You may be asked to swallow a pill or liquid with urea 15 minutes before you exhale into the bag. The doctor will compare the carbon levels of your breaths. 

An elevated carbon level means a presence of urease— the enzyme that H. pylori bacteria produces.

Stool Test

A stool test can check for the presence of H. pylori in your digestive tract. You’ll need to collect a small sample of your stool and send it to a lab.

Test results may come out in two to three days. It can help doctors conclude if an H. pylori infection is causing your symptoms.

Upper Endoscopy 

It’s an invasive diagnostic test that uses a thin, lighted tube called an endoscope.

The endoscope has a camera on one end. It goes into your throat and gives a closer look at the lining of your esophagus, stomach, and upper part of your small intestine. 

During endoscopy, the doctor may take a small tissue sample or biopsy. They can run a test to check for urease or H. pylori.


A healthcare professional may use less invasive methods to test you for H. Pylori infection. They may examine a sample of your blood, stool, and breath. Sometimes, they may use an invasive procedure like upper endoscopy to examine your gastrointestinal (GI) lining closely.

H. Pylori Treatment

You may not need treatment if you don’t have any symptoms of an H. pylori infection. 

However, if your doctor confirms a positive diagnosis, they might prescribe antibiotics and proton pump inhibitors (PPI) to help treat your infection and relieve your symptoms.

You must also avoid taking nonsteroidal anti-inflammatory drugs (NSAIDs) once you have an H. pylori diagnosis. They can increase your chances of developing an ulcer.

Here are the common treatments for H. pylori infections:

  • Antibiotic drugs — kill or lower the population of harmful bacteria 
  • Proton pump inhibitors (PPI) — stop your stomach from producing too much acid
  • Bismuth subsalicylate — protects the lining of your stomach from acids
  • H2 blockers — decrease your stomach acid by blocking histamine

After four weeks of treatment, you may need to take another Helicobacter pylori test. It can help your doctor assess if the medications cleared the infection. 

Based on your results, they can tell if you need another round of H. pylori treatment. People who develop stomach ulcers from H. pylori infections may also be treated for their condition.

How to Prevent H. Pylori Infection

Currently, no vaccines can protect us from an H. pylori infection. However, some scientists are working on an H. pylori vaccine and have had positive results.6

In the meantime, you can avoid an H. pylori infection by practicing good hygiene, such as:

  • Drinking clean water
  • Using clean water for cooking
  • Making sure that you cook your food thoroughly
  • Washing your hands before eating and preparing food

Your doctor may suggest dietary changes, such as adding more fruits, vegetables, and fiber to your meals. These foods encourage the growth of friendly microbes in your gut.

Most people don’t experience symptoms or health problems despite having H. pylori bacteria in their gut. Screening may help you seek the proper treatment if you have another condition.


Treatment for H. Pylori infection includes antibiotic drugs and medications for decreasing your stomach's acid production, like Proton pump inhibitors (PPI) and H2 blockers. No vaccines are available yet to protect us from H. Pylori. But you can prevent the spread of H. Pylori bacteria through good hygiene and a healthy diet.

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Updated on March 23, 2023
Cristine Santander
Cristine Santander
Content Contributor
Cristine Santander is a content writer for KnowYourDNA. She has a B.S. in Psychology and enjoys writing about health and wellness.
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