Helicobacter pylori (H. pylori)

What is H. pylori?

Helicobacter pylori is a bacterium that lives in the lining of the stomach. Guts UK states that up to 2 in 5 people in the UK have it, and that prevalence is higher in some groups (for example, people with learning disabilities). Most people never know they carry it.

According to Guts UK, H. pylori does not cause symptoms in 8 to 9 out of 10 people. When it is found, clinicians still usually offer eradication treatment because clearing the infection lowers the risk of later complications.

Why it matters

NICE BNF states that H. pylori is one of the most common causes of peptic ulcer disease, associated with about 95% of duodenal ulcers and 70–80% of gastric ulcers. It is also linked to acute and chronic gastritis, gastric cancer, and gastric MALT lymphoma. Eradication reduces the risk of peptic ulcer disease, ulcer bleeding, gastric malignancy, and recurrence of gastritis or peptic ulcers.

NSAID use (including ibuprofen and aspirin) may have an additive effect with co-existent H. pylori, further increasing ulcer and bleeding risk — but that does not mean H. pylori alone causes every ulcer.

Symptoms (when present)

Most carriers have no symptoms. When symptoms occur they can overlap with indigestion and ulcer disease:

• Upper abdominal discomfort or pain
• Indigestion, bloating, or nausea
• Symptoms of peptic ulcer disease (see our stomach ulcer page)

Most everyday indigestion is functional dyspepsia, but H. pylori still needs to be considered on the NICE dyspepsia pathway.

How it is diagnosed

• Urea breath test — recommended non-invasive option
• Stool antigen test (SAT) — recommended non-invasive option
• Validated laboratory serology — where breath/stool are not suitable
• Endoscopy with biopsy — when alarm features or other indications for endoscopy apply

NICE BNF and UKHSA do not recommend office-based (near-patient) serology. Timing matters: breath and stool tests should not be done within 2 weeks of PPIs or 4 weeks of antibiotics.

Test-and-treat in dyspepsia

NICE CG184 and BSG education materials cover test-and-treat for H. pylori as part of adult dyspepsia care (alongside pathways that also discuss GERD). In people with functional dyspepsia, NICE BNF notes that routine retesting after eradication is not recommended.

Approaches people discuss

H. pylori care is clinician-led. The options below are pathways people hear about in clinic — not DIY antibiotic plans.

• Established Test-and-treat for H. pylori in appropriate dyspepsia pathways (urea breath test or stool antigen; validated lab serology when needed). Sources: NICE CG184; BSG; NICE BNF; UKHSA.
• Established Clinician-prescribed eradication therapy when H. pylori is confirmed, to reduce ulcer, bleeding, and gastric malignancy risk. Regimens use antibiotics guided by local antimicrobial advice because clarithromycin resistance is rising. Sources: NICE BNF; UKHSA.
• Established Reviewing NSAID risk with a clinician when H. pylori is also present — additive ulcer risk, not a reason to stop prescribed medicines without advice. Sources: NICE BNF.

What not to self-manage

These are cautions, not approaches people discuss:

• Do not assume H. pylori explains your symptoms — most carriers are asymptomatic; presence is not the same as causation (Guts UK).
• Do not stop NSAIDs without medical advice — additive risk with H. pylori matters, but self-stopping prescribed medicines can be harmful (NICE BNF).
• Do not invent your own antibiotic course — eradication needs a prescribed regimen; resistance patterns change and local guidance applies (NICE BNF; UKHSA).
• Do not book breath or stool tests too soon after PPIs or antibiotics — wait at least 2 weeks after PPIs and 4 weeks after antibiotics for reliable results (NICE BNF; UKHSA).