Health condition · Clinically reviewed
Gastritis, inflammation of the stomach lining.
A common condition with many causes — H. pylori, NSAIDs, alcohol and autoimmune. Diagnosis and treatment focus on the underlying cause.
Why trust this guide
- 01
Clinically reviewed
Written by our editorial team and reviewed by a registered UK clinician before publication.
- 02
Sourced from guidance
Every claim is checked against NICE, BSG or peer-reviewed sources you can see at the end.
- 03
Current for 2026
Reflects current UK guidance on H. pylori eradication, PPIs and when to consider endoscopy.
Key facts
Gastritis at a glance.
The essentials, in plain English — what gastritis is, what usually causes it, how it is confirmed, and what to expect from treatment.
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What it is
Inflammation of the stomach lining — either a histological finding on biopsy or a clinical picture of upper-gut symptoms.
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Main causes
H. pylori infection, NSAIDs, alcohol, and autoimmune disease account for most cases.
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Global picture
H. pylori is the leading cause of gastritis worldwide.
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Reference test
Upper GI endoscopy with biopsy is the reference standard for diagnosis and cause.
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Most resolve
Eradicating H. pylori or removing the trigger resolves the majority of cases.
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A specific risk
Autoimmune gastritis carries a defined long-term gastric cancer risk and needs surveillance.
Why this guide matters
Common, treatable, and worth taking seriously.
Most gastritis is treatable once the cause is identified — but a small group needs faster investigation. The three points below shape everything else on this page.
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The cause dictates the cure
H. pylori, NSAIDs, alcohol or autoimmune — identifying which changes the whole plan.
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Eradication resolves most cases
Where H. pylori is the driver, triple therapy cures the gastritis in most people.
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Red flags decide who scopes
Haematemesis, melaena or weight loss — endoscopy without delay.
How the diagnosis is made
From first symptoms to a clear plan.
The steps a UK GP will normally follow, in order — so you know what to expect and why.
Phase 1 · Recognising
History, medication review and first tests
Phase 2 · Confirming
Endoscopy, bloods and autoimmune serology
Phase 3 · Managing
B12 and specialist follow-up
- 01
Recognising
Symptom + medication history
Epigastric pain, nausea, bloating — plus a careful look at NSAIDs, alcohol and other drugs.
- 02
Recognising
H. pylori testing
Urea breath test or stool antigen — the first-line non-invasive tests when there are no red flags.
- 03
Confirming
Upper GI endoscopy + biopsy
The reference test — visualises the mucosa and confirms cause histologically.
- 04
Confirming
CRP + FBC
Screens for inflammation and anaemia — a useful baseline in persistent dyspepsia.
- 05
Confirming
Autoimmune serology
Parietal cell and intrinsic factor antibodies where autoimmune gastritis is suspected.
- 06
Managing
Vitamin B12
Test for B12 deficiency — the classic downstream consequence of autoimmune gastritis.
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Managing
Gastroenterology consultation
For confirmed autoimmune disease, refractory cases, or where surveillance is needed.
Typical timeline: 2-6 weeks from first test to a settled plan.
Symptoms
What gastritis actually feels like.
Upper-gut symptoms are common and often overlap with reflux or ulcer disease. It is the pattern — and the red flags — that matter.
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Epigastric pain
A gnawing or burning discomfort in the upper abdomen — often related to meals.
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Nausea
A common early feature, sometimes without other symptoms.
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Vomiting
Occasional or persistent — persistent vomiting always warrants review.
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Post-meal fullness
Feeling uncomfortably full soon after starting to eat.
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Bloating
Distension and belching, often paired with early satiety.
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Autoimmune features
Fatigue, pallor and neurological symptoms from associated B12 deficiency.
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Black tarry stools
Melaena — a sign of upper GI bleeding, needs urgent assessment.
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Red-flag symptoms
Haematemesis, melaena or weight loss — urgent 2-week-wait endoscopy referral.
Treatment
How gastritis is treated in the UK.
Deal with the cause, protect the mucosa, replace what is missing — what each option does and where it fits.
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H. pylori eradication
7-14 days of triple therapy — a PPI plus two antibiotics — cures most H. pylori-related gastritis.
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Stop NSAIDs where possible
Withdrawing the trigger allows the mucosa to heal — review any regular NSAID or aspirin use.
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PPIs
Omeprazole, pantoprazole or lansoprazole reduce acid and support mucosal healing.
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Sucralfate
A mucosal protectant used in selected cases to coat and shield the stomach lining.
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B12 injections
For autoimmune gastritis with B12 deficiency — parenteral replacement is standard.
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Alcohol reduction
Cutting or stopping alcohol removes a direct mucosal irritant and speeds recovery.
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Endoscopic surveillance
For autoimmune gastritis — periodic endoscopy screens for gastric neoplasia.
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Dietary trigger avoidance
Identifying and avoiding individual triggers — spicy or acidic foods, large late meals — helps symptoms.
What this guide is based on
The sources behind every claim on this page.
UK national guidance and specialist society standards, current at the time of last review.
Key references
Guidelines and standards we relied on.
A quiet reminder
This guide is for information, not medical advice.
Your GP knows your history and can tell you which parts apply to you. If in doubt, see them.
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NICE. Dyspepsia and gastro-oesophageal reflux disease in adults (CG184).
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British Society of Gastroenterology. Guidelines on H. pylori and gastritis.
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Maastricht VI / Florence Consensus Report on H. pylori management.
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NHS. Gastritis: information for patients.
Red flags
When gastritis stops being routine.
Most gastritis settles with treatment. These are the situations where it needs urgent attention.
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Haematemesis
Vomiting blood — bright red or coffee-ground — call 999.
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Melaena
Black tarry stool — a sign of upper GI bleeding, urgent assessment.
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Weight loss with dyspepsia
Unexplained weight loss alongside upper-gut symptoms — urgent GP.
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Anaemia
New iron-deficiency anaemia with dyspepsia — possible chronic bleeding.
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Vitamin B12 deficiency
Points to autoimmune gastritis — needs confirmation and long-term follow-up.
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Persistent vomiting
Ongoing vomiting or inability to keep fluids down — urgent review.
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Gastric ulcer on endoscopy
Biopsy and follow-up endoscopy are required to exclude malignancy.
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Family history gastric cancer
Lowers the threshold for endoscopy and closer follow-up.
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Autoimmune gastritis
A defined long-term gastric cancer risk — surveillance is appropriate.
Living with it
A manageable condition, when the cause is found.
Four things that make the biggest difference day to day — trigger, diet, long-term medication and autoimmune follow-up.
A quiet reminder
Consistency beats intensity, every time.
Small, steady changes — kept up for months — do more than a heroic week that does not last.
- 01 Trigger
Remove the cause where you can
Most gastritis resolves once the trigger — H. pylori, NSAIDs, alcohol — is dealt with.
- 02 Diet
Small changes, kept up
Smaller meals, avoiding personal trigger foods and moderating alcohol make the biggest day-to-day difference.
- 03 Long-term
PPIs are effective — review annually
Where PPIs are needed long-term, an annual review to step down to the lowest effective dose is sensible.
- 04 Autoimmune
A specific follow-up plan
Autoimmune gastritis needs B12 replacement and endoscopic surveillance at agreed intervals.
Frequently asked
Everything we get asked about gastritis.
Quick answers on causes, testing, H. pylori, autoimmune disease and when to worry.
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What causes gastritis?
The main causes are H. pylori infection, NSAIDs, alcohol and autoimmune disease. H. pylori is the leading cause worldwide.
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How is gastritis diagnosed?
By history and non-invasive H. pylori testing (breath test or stool antigen) in the first instance. Upper GI endoscopy with biopsy is the reference test and is used for red flags, refractory symptoms, or when the cause needs to be confirmed.
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Is H. pylori serious?
It is treatable and eradication resolves most gastritis. Left untreated, chronic H. pylori is linked to ulcers and — over decades — an increased risk of gastric cancer.
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What is autoimmune gastritis?
A condition where the immune system attacks the acid- and intrinsic-factor-producing cells of the stomach. It causes B12 deficiency and carries a specific long-term gastric cancer risk, so surveillance is part of care.
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Can NSAIDs really cause gastritis?
Yes — regular NSAID or aspirin use is one of the most common causes. Where possible, stopping or reducing the drug allows the mucosa to heal.
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When should I call 999?
Vomiting blood, passing black tarry stool, or severe unrelenting abdominal pain — do not wait, call 999 or attend A&E.
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