Health condition · Clinically reviewed
Aortic aneurysm, screening, surveillance and modern endovascular repair.
Abdominal or thoracic aortic dilatation — often silent until it ruptures. NHS AAA screening picks up most; surveillance and endovascular repair transform outcomes.
Why trust this guide
- 01
Clinically reviewed
Written by our editorial team and reviewed by a registered UK clinician before publication.
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Sourced, not summarised
Every claim is checked against NICE, the Vascular Society or a peer-reviewed source you can see at the end.
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Updated for 2026
Reflects current UK guidance on screening, surveillance thresholds and endovascular repair.
Key facts
Aortic aneurysm at a glance.
The essentials, in plain English — what it is, how it is picked up, and how the UK treats it in 2026.
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What it is
Localised dilatation of the aorta — ≥3 cm in the abdomen or ≥4 cm in the thoracic aorta.
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How it presents
Silent in most patients until it ruptures — which is why screening matters.
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UK screening
The NHS AAA Screening Programme offers ultrasound to men in the year they turn 65.
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Modern repair
EVAR (endovascular aneurysm repair) has largely replaced open surgery for suitable AAAs.
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Thoracic disease
Marfan syndrome and other connective-tissue disorders drive many thoracic aneurysms.
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Rupture
A surgical emergency — sudden severe abdominal or back pain with collapse means call 999.
Why this guide matters
A silent problem with a very loud ending.
Almost every aortic aneurysm story is decided long before it ruptures — screening, surveillance and modern repair do the heavy lifting.
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Screening changes outcomes
The NHS AAA screen roughly halves aneurysm-related mortality in the men it invites.
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Millimetres matter
Surveillance thresholds — and repair thresholds — are measured in fractions of a centimetre.
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EVAR has changed the odds
Endovascular repair means shorter stays and faster recovery for most patients today.
How the diagnosis is made
From first ultrasound to a clear plan.
The steps a UK vascular team will normally follow, in order — so you know what to expect and why.
Phase 1 · Detecting
Screening and confirmatory imaging
Phase 2 · Confirming
Cardiac work-up, genetics and MDT
Phase 3 · Managing
Repair choice and follow-up imaging
- 01
Detecting
Screening ultrasound (AAA screen)
The NHS AAA Screening Programme offers a one-off ultrasound to men in the year they turn 65.
- 02
Detecting
CT angiogram to confirm and size
A contrast CT maps the aneurysm precisely — diameter, length, neck and side branches.
- 03
Confirming
Cardiac work-up
ECG, echocardiogram and risk assessment before any planned repair.
- 04
Confirming
Genetic screen
Considered for thoracic disease, young patients and a family history of aortopathy.
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Confirming
Vascular MDT
A specialist team reviews the imaging and agrees whether to watch, repair, and by what route.
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Managing
Consider EVAR / TEVAR vs open
Endovascular repair is now the default for most anatomically suitable AAAs; open surgery still has a role.
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Managing
Follow-up imaging after repair
Lifelong surveillance — usually CT or duplex — to check for endoleak and stent-graft migration.
Typical timeline: weeks to months from screen to a settled surveillance or repair plan.
Symptoms
What an aortic aneurysm actually feels like.
Usually, nothing — until it doesn’t. Here is what to look for, and when to seek urgent care.
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Asymptomatic (usually)
Most aneurysms cause no symptoms and are picked up on screening or as an incidental finding on scans.
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Pulsatile abdominal mass
A pulsing lump above the belly button, sometimes noticed lying flat — always worth checking.
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Back pain
A deep, aching lower back or flank pain can be the first symptom of an expanding aneurysm.
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Leg pain (embolic)
Sudden painful, cold or pale limb from a clot thrown off the aneurysm sac.
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Family history of AAA
A first-degree relative with an aneurysm doubles your risk — mention it to your GP.
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Marfan / connective tissue
Marfan, Loeys-Dietz and Ehlers-Danlos syndromes are strongly linked to thoracic aortic disease.
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Uncontrolled hypertension
Sustained high blood pressure accelerates aneurysm growth and dissection risk.
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When to seek urgent care
Sudden severe abdominal or back pain with feeling faint or collapse — call 999 (possible rupture).
Treatment
How aortic aneurysms are treated in the UK.
Watch, treat medically, or repair — what each option does, and when it is chosen.
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Surveillance imaging
Small aneurysms are monitored with regular ultrasound or CT rather than operated on straight away.
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Blood pressure control
Tight BP targets reduce wall stress and slow aneurysm expansion.
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Statin therapy
Standard for cardiovascular risk reduction — most patients with aortic disease qualify.
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Smoking cessation
The single biggest modifiable driver of AAA growth and rupture. Stopping helps at any age.
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EVAR (endovascular)
A stent-graft delivered through the groin arteries — shorter recovery, now the default for suitable AAAs.
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TEVAR (thoracic)
The thoracic-aorta equivalent of EVAR, for descending thoracic aneurysms and some dissections.
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Open aortic repair
Still preferred for young patients, unfavourable anatomy or connective-tissue disease.
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Endovascular emergency repair
Ruptured AAAs are increasingly repaired with an emergency stent-graft in specialist centres.
What this guide is based on
The sources behind every number 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 or vascular team knows your history and can tell you which parts apply to you. If in doubt, ask.
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National Institute for Health and Care Excellence (NICE). Abdominal aortic aneurysm: diagnosis and management (NG156).
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Vascular Society of Great Britain and Ireland. Standards for aortic aneurysm care.
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European Society for Vascular Surgery. Clinical practice guidelines on aortic disease.
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NHS Abdominal Aortic Aneurysm Screening Programme. Service specification and outcomes.
Red flags
When an aortic aneurysm becomes an emergency.
Most of the time, aneurysm care is slow and measured. These are the situations where it stops being slow — and you should act today.
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Suspected rupture
Sudden severe abdominal or back pain with collapse or hypotension — call 999.
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Rapid AAA expansion
More than 0.5 cm growth in six months warrants urgent vascular review.
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Post-EVAR endoleak
New back pain, an enlarging sac or contrast filling outside the stent on imaging.
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Marfan aortic dissection
Tearing chest or interscapular pain in anyone with a known aortopathy — 999.
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Bicuspid aortic valve + aneurysm
A combination that raises the threshold for surgery — needs a specialist opinion.
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Post-repair infection
Fever, back pain or malaise weeks to years after a graft — rare but serious.
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Uncontrolled hypertension
BP that will not settle on treatment accelerates growth and dissection risk.
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Family cascade needed
A new diagnosis of thoracic aneurysm should trigger imaging of first-degree relatives.
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Pregnancy with aortopathy
Pregnancy raises aortic stress — plan care with a specialist cardiac obstetric team.
Living with it
A long-term condition, but a very manageable one.
Four things that make the biggest difference between diagnosis and any repair — habits, monitoring, medication and reviews.
A quiet reminder
Consistency beats intensity, every time.
Small, steady changes — kept up for months — protect the aorta better than a heroic week that doesn’t last.
- 01 Daily habits
Stop smoking, keep moving
Stopping smoking and staying active are the two things that most reliably slow aneurysm growth.
- 02 Monitoring
Keep every surveillance scan
Growth is measured in millimetres over months — missed scans lose that thread.
- 03 Medication
Take BP and statin therapy as agreed
Small daily habits — one tablet, one BP reading — are what protect the aorta between scans.
- 04 Reviews
Lifelong follow-up after repair
Even a successful EVAR needs regular imaging to check the stent-graft is still sealing.
Frequently asked
Everything we get asked about aortic aneurysm.
Quick answers on screening, surveillance thresholds, EVAR vs open repair, family risk and when to worry.
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What is an aortic aneurysm?
A localised bulge in the aorta — 3 cm or more in the abdomen, or 4 cm or more in the thoracic aorta. Most cause no symptoms until they leak or rupture.
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Who is offered NHS AAA screening?
Men in the year they turn 65 are invited for a one-off abdominal ultrasound. Women and younger men can be screened privately if there is a family history or other risk factor.
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How is an aortic aneurysm treated?
Small aneurysms are watched with regular scans. Larger or fast-growing aneurysms are repaired — usually by EVAR (a stent-graft through the groin), sometimes by open surgery.
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What is EVAR?
Endovascular Aneurysm Repair — a stent-graft delivered through the femoral arteries in the groin. Recovery is faster than open surgery and it is now the default for most anatomically suitable AAAs.
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Is an aortic aneurysm hereditary?
Family history matters. Around one in five people with an AAA has an affected first-degree relative, and thoracic aneurysms are often linked to inherited connective-tissue disorders such as Marfan syndrome.
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When is an aortic aneurysm an emergency?
Sudden severe abdominal, back or chest pain — especially with feeling faint, sweating or collapse — could mean rupture or dissection. Call 999.
Related content
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