H. pylori infection: symptoms, testing and treatment

About half the world carries H. pylori, yet many people never feel sick. If you have recurring stomach pain, bloating, or long-lasting heartburn, this bacteria could be the cause—and it's one you can test for and treat.

H. pylori is a common stomach bacterium that can damage the protective lining of your stomach and upper small intestine. That damage can cause gastritis and peptic ulcers. Not everyone infected will get symptoms, but when they do, they tend to be steady and bothersome.

Watch for these signs: a burning pain between meals or at night, bloating, frequent burping, nausea, unexplained weight loss, or black/tarry stools. If you get sudden severe stomach pain, fainting, or vomiting blood, seek emergency care—those can be warning signs of a bleeding ulcer.

How it's diagnosed

There are a few reliable tests. The urea breath test (UBT) is quick and accurate: you drink a special solution and breathe into a bag to check for the bacteria. Stool antigen tests look for H. pylori proteins in a poop sample and are also commonly used. Blood antibody tests exist but can’t tell if the infection is current or old. When doctors need a closer look, they use endoscopy with a biopsy—this is more invasive but useful for ulcers or unusual symptoms.

One practical tip: stop proton pump inhibitors (PPIs) like omeprazole at least 2 weeks before a breath or stool test, and finish antibiotics for at least 4 weeks before testing for cure. Otherwise the test can give a false negative.

Treatment and what to expect

Treatment typically combines two antibiotics plus a stomach acid reducer. Traditional "triple therapy" often uses clarithromycin and amoxicillin (or metronidazole) with a PPI for 10–14 days. When resistance is a concern, doctors use quadruple therapy with bismuth. Follow your prescription exactly—missing doses raises the chance the treatment won’t work.

Side effects can include nausea, diarrhea, and a metallic taste. Probiotics may ease diarrhea for some people, but they don’t replace antibiotics. If symptoms persist after treatment, your doctor may order a repeat breath or stool test at least 4 weeks after finishing antibiotics to confirm eradication.

To lower your risk of catching H. pylori, focus on hygiene: wash hands, drink clean water, and avoid sharing eating utensils in places with poor sanitation. Stop smoking if you can—it slows ulcer healing. Avoid long-term NSAID use unless advised by a doctor, since NSAIDs increase ulcer risk on top of any infection.

If you suspect H. pylori or have ongoing stomach problems, make an appointment. A clear test and the right treatment usually resolve the issue, and getting treated cuts the chance of ulcers returning. Keep records of tests and meds, and ask about follow-up testing to be sure the infection is gone.