Overview
Helicobacter pylori (H. pylori for short) is a bacterium that can live for years in the lining of the stomach. It causes chronic gastritis and is one of the main causes of stomach and duodenal ulcer. It is also linked to a higher risk of stomach cancer and MALT lymphoma — although the vast majority of infected people never develop these diseases.
This page focuses on practical questions: which test is accurate, how the infection is treated and how cure is confirmed.
Symptoms
Many people have no symptoms. When there are complaints, they may be pain or burning in the upper abdomen, nausea and dyspepsia. Heartburn and bloating do not necessarily indicate the presence of the bacterium.
Which test is used
| Test | What it shows | When it is used |
|---|---|---|
| Urea breath test | Active infection | Diagnosis and check after treatment |
| Stool antigen | Active infection | Diagnosis and check after treatment |
| Biopsy during gastroscopy | Active infection + condition of the mucosa | When gastroscopy is needed for other reasons |
| Antibodies in the blood (serology) | Contact with the bacterium, current or past | Not used for confirmation or for checking cure |
No test is 100% accurate. Some medicines — antibiotics, bismuth and acid-lowering drugs (PPIs) — can give a false negative result. For this reason, before the test the doctor may instruct you to temporarily stop some of them.
Who should be tested
Testing is recommended for people with a current or past ulcer, for some cases of dyspepsia and for certain groups at increased risk, even without symptoms (e.g. a family history of stomach cancer). The decision is made individually; not everyone who is tested needs a gastroscopy.
Treatment
A confirmed infection is treated with a combination of medicines — usually a strong acid suppressant together with two or more antibiotics, sometimes also bismuth. Many regimens recommended today last 14 days.
The regimen is chosen by the doctor according to the bacterium's resistance to antibiotics, allergies and the antibiotics you have taken before. Regimens with clarithromycin are not used automatically, because resistance to it has increased.
- Take the medicines regularly to the end, even if you feel well.
- Do not use leftover antibiotics from another treatment and do not repeat a regimen that has failed on your own.
- If you have side effects, talk to your doctor before stopping.
Check after treatment
Cure is confirmed with a test, not just by improvement of symptoms.
- The test is done at least 4 weeks after finishing the antibiotics and bismuth.
- Acid-lowering drugs (PPIs) are usually stopped 2 weeks before the test, as instructed by the doctor.
Diet and probiotics
No diet eliminates the bacterium. Probiotics do not replace treatment and their benefit depends on the product.
Key sources
This information is educational and does not replace a visit to the doctor. Do not change your treatment without consulting your doctor. Updated: October 2026.