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Blood test

H. pylori blood and breath test

H. pylori blood and breath test: what it measures, why a doctor orders it, how to prepare, and what a high or low result can mean - with private and NHS access routes in the UK.

Key facts

At a glance

  • What it measures: evidence of Helicobacter pylori, the stomach bacterium behind most ulcers - by antibody blood test, urea breath test or stool antigen.

  • Why it is ordered: when recurrent indigestion, suspected ulcers or unexplained iron deficiency prompts a search for the infection.

  • For the breath and stool tests, acid-suppressing PPIs are stopped for two weeks and antibiotics for four, or a live infection can be missed.

  • Reference ranges: the blood antibody test stays positive long after treatment, so breath or stool testing is preferred to confirm current infection or cure. Every laboratory publishes its own interval, so the range printed on your report is the one that applies to you.

  • A raised result or positive breath or stool result means current infection, which is treated with a short course of combined antibiotics and acid suppression. A low result or negative result on a properly prepared breath or stool test makes current infection unlikely.

  • Results usually take one to three working days, depending on the laboratory.

The full picture

What this test tells you, and how to get it

The H. pylori blood and breath test measures evidence of Helicobacter pylori, the stomach bacterium behind most ulcers - by antibody blood test, urea breath test or stool antigen. Doctors most often request it when recurrent indigestion, suspected ulcers or unexplained iron deficiency prompts a search for the infection. For the breath and stool tests, acid-suppressing PPIs are stopped for two weeks and antibiotics for four, or a live infection can be missed. The blood antibody test stays positive long after treatment, so breath or stool testing is preferred to confirm current infection or cure, and reference intervals genuinely differ between laboratories, so no single number should be treated as a universal cut-off - your result is always read against the range printed on your own report. Broadly, a raised result or positive breath or stool result means current infection, which is treated with a short course of combined antibiotics and acid suppression, while a low result or negative result on a properly prepared breath or stool test makes current infection unlikely, and either finding is interpreted alongside your symptoms, medication and other results rather than in isolation. Results usually take one to three working days, depending on the laboratory.

In the UK there are two routes to this test. Your NHS GP can arrange it free of charge when it is clinically indicated, though getting the appointment, the blood draw and the follow-up discussion can add days to weeks depending on local demand. Privately, the H. pylori blood and breath test can usually be booked within days - through a private GP, a walk-in phlebotomy clinic or a self-request home-testing service - and breath test kits are widely available both on the NHS and privately. A private result still deserves a clinician's interpretation: an isolated number without context is where most confusion about blood tests begins.

A quiet reminder

This guide is for information, not medical advice.

Your own clinician knows your history and can tell you which parts apply to you. Reference ranges vary between laboratories - always read your result against the interval printed on your own report. Next review of this page: 2027-09-27.

Frequently asked

Common questions about H. pylori blood and breath test.

Quick, plain-English answers to what people ask us most.

  • What is an H. pylori blood and breath test?

    These are two different ways of checking for Helicobacter pylori, a common stomach bacterium linked to gastritis and ulcers. The blood test looks for antibodies your immune system has made against the bacterium, while the breath test detects active infection by measuring a marker gas after you swallow a special substance.

  • Why would a doctor order this test?

    It's used to investigate symptoms like indigestion, stomach pain, bloating or a history of peptic ulcers, and to confirm the bacterium has been successfully cleared after treatment. The breath or stool test is generally preferred for this purpose, as the blood antibody test can stay positive even after successful treatment.

  • Do I need to prepare for this test?

    For the breath test, you'll usually need to avoid antibiotics for around four weeks and certain acid-reducing medications for one to two weeks beforehand, and often fast for a few hours; your clinic will confirm exact timings. The blood test typically needs no special preparation.

  • What happens during the test?

    The blood test involves a simple sample taken from your arm. The breath test involves swallowing a capsule or liquid containing a labelled substance, then breathing into a collection device before and after a short waiting period, which is quick and non-invasive.

  • Does it hurt or carry any risks?

    The blood test involves a brief needle prick, and the breath test has no needles and no known risks. Both are very well tolerated.

  • How long do results take?

    Blood test results are often available within a few days. Breath test results can take slightly longer as the sample needs laboratory analysis, though many private providers turn results around within a similar timeframe.

  • What do abnormal results mean, and what happens next?

    A positive result usually means H. pylori infection is present or, for the antibody test, has been present at some point, and your doctor will typically recommend a course of treatment combining antibiotics and acid-suppressing medication. A follow-up breath or stool test is often used a few weeks after treatment to confirm the infection has cleared.

  • How much does this test cost privately, and is it available on the NHS?

    H. pylori testing is available on the NHS, usually through your GP. Private testing is typically available within days, with results reviewed by a doctor; cost varies by provider.

  • Is the test accurate and reliable?

    The breath test is considered highly accurate for detecting active infection, both before and after treatment. The blood antibody test is useful for a first check but less reliable for confirming clearance, which is why a breath or stool test is preferred afterwards.

  • How do I book this test privately, and how quickly can I be seen?

    You can book privately with or without a referral, and appointments, including the necessary preparation guidance, are usually available within a few days.