Patient guide · Vascular ultrasound
Abdominal aortic aneurysm screening, a one-off ultrasound that can save your life.
A single, painless abdominal ultrasound to measure the size of the abdominal aorta. Offered on the NHS to men in the year they turn 65 and available privately for women and higher-risk adults. Detects aneurysms early, before they rupture.
Reviewed by Pulse Atlas Editorial Board () · Last reviewed 2026-07-30 · Next review 2027-07-30 · 6 min read
Why it matters
- 01
A one-off scan that saves lives
A single painless ultrasound in the year you turn 65 has been shown to reduce AAA-related death by around 40% in men.
- 02
Fast, painless, radiation-free
Ten to fifteen minutes, no needles, no dye, no fasting for most protocols — same-day results.
- 03
Clear onward pathway
If an aneurysm is found, we route surveillance or vascular-surgery review based on the diameter.
Key facts
AAA screening in six lines.
A quick, plain-English summary of the test, the size bands, and who is most likely to benefit.
| Fact | Detail |
|---|---|
| Definition | An ultrasound scan to measure the diameter of the abdominal aorta. |
| The test | Painless, 10–15 minute abdominal ultrasound. |
| What counts as an AAA | An aortic diameter of 3 cm or more. |
| Follow-up bands | Small (3.0–4.4 cm) surveillance · medium (4.5–5.4 cm) closer follow-up · large (≥ 5.5 cm) vascular referral. |
| Who is at highest risk | Men aged 65 and over, and current or ex-smokers. |
| Impact of screening | Timely repair prevents around 95% of AAA-related deaths in screened populations. |
Preparation
What to expect, step by step.
From walking in to walking out — the scan itself takes ten to fifteen minutes.
Phase 1 · Before your scan
No fasting, no special prep
Phase 2 · On the day
~10–15 minutes at the clinic
Phase 3 · After
Same-day result and follow-up
- 01
Before
No fasting for most protocols
Eat, drink and take medication as normal on the day of your scan unless your clinic specifies otherwise.
- 02
Before
Wear loose, comfortable clothing
A two-piece outfit is easiest so the abdomen can be exposed without full undressing.
- 03
On the day
Gel applied to the abdomen
A warm, water-based gel is spread over the abdomen so the probe glides smoothly and images come through clearly.
- 04
On the day
Curvilinear probe sweeps the aorta
A low-frequency curvilinear ultrasound probe is swept across the abdomen to visualise the full length of the abdominal aorta.
- 05
On the day
Transverse and longitudinal planes
Measurements of the aortic diameter are taken in both transverse and longitudinal planes to confirm the maximum size.
- 06
After
Results issued the same day
The sonographer or reporting clinician gives your result at the end of the appointment — normal, small, medium or large.
- 07
After
Follow-up scheduled based on size
If an aneurysm is found, a surveillance interval or vascular referral is arranged straight away.
What it shows
What an AAA screening ultrasound can pick up.
The primary question is aortic diameter, but the sweep also inspects the iliac arteries and adjacent abdominal organs.
-
Aortic diameter
The primary measurement — normal, borderline or aneurysmal in the transverse and longitudinal planes.
-
Small AAA (3.0–4.4 cm)
Small aneurysm — surveillance ultrasound at 12-month intervals.
-
Medium AAA (4.5–5.4 cm)
Medium aneurysm — closer follow-up, typically every three months.
-
Large AAA (≥ 5.5 cm)
Large aneurysm — direct referral to vascular surgery for repair discussion.
-
Aortic dissection flap (rare incidental)
An intimal flap suggesting dissection is a rare but important incidental finding.
-
Iliac artery aneurysm
The iliac arteries are inspected for concomitant aneurysmal disease.
-
Related abdominal pathology
Incidental gallstones, renal or hepatic lesions may be picked up during the sweep.
-
Red flag: rapidly expanding or symptomatic AAA
Rapid growth or new abdominal / back pain warrants urgent vascular-surgery review.
Next steps
What happens after your screening scan.
The pathway depends on aortic diameter and growth rate — from reassurance through surveillance to surgical repair.
-
Reassurance if normal (< 3 cm)
A normal scan is highly reassuring — the lifetime risk of a first AAA developing later is low, and routine re-screening is not required.
-
Repeat ultrasound at 12 months (small AAA)
For aneurysms measuring 3.0–4.4 cm, annual surveillance ultrasound is the standard pathway.
-
Repeat ultrasound at 3 months (medium AAA)
For aneurysms measuring 4.5–5.4 cm, three-monthly ultrasound is used to detect rapid growth.
-
Vascular surgery referral (≥ 5.5 cm or > 1 cm/yr)
Aneurysms at or above 5.5 cm, or growing faster than 1 cm per year, are referred for repair discussion.
-
Optimise cardiovascular risk
Blood pressure control, statin therapy where indicated, and smoking cessation slow aneurysm growth and reduce cardiovascular risk.
-
Endovascular aneurysm repair (EVAR)
A stent-graft delivered via the femoral arteries — lower short-term morbidity, suitable for many anatomies.
-
Open surgical repair
A traditional open procedure to replace the aneurysmal segment with a graft — durable and used where anatomy precludes EVAR.
-
Emergency vascular surgery for rupture
Sudden severe abdominal or back pain with collapse is a surgical emergency — 999 and immediate transfer to a vascular unit.
Red flags
When AAA becomes an emergency.
These are the presentations that warrant urgent — sometimes 999 — action rather than a routine appointment.
-
Sudden severe abdominal or back pain
The classic presentation of AAA rupture — a surgical emergency requiring 999 and immediate vascular assessment.
-
Pulsatile abdominal mass
A palpable, pulsatile mass in the abdomen warrants urgent imaging and vascular review.
-
Rapid expansion (> 1 cm per year)
Growth exceeding 1 cm per year on surveillance is an indication for vascular-surgery referral irrespective of absolute size.
-
Blue-toe syndrome
Sudden painful, cyanotic toes suggest embolic disease from aneurysmal thrombus — vascular review indicated.
-
Aortic dissection
Tearing chest or back pain with an intimal flap on imaging is a distinct vascular emergency — 999.
-
Ruptured AAA with hypotension
Rupture with collapse and low blood pressure is the highest-acuity vascular presentation — resuscitation and emergency repair.
-
Concomitant iliac aneurysm
An iliac aneurysm alongside an AAA changes surgical planning and merits vascular input.
-
Post-EVAR endoleak
Persistent flow within the aneurysm sac after stent-graft repair requires surveillance and, sometimes, re-intervention.
-
Post-operative infection
Fever, wound discharge or graft-site pain after AAA repair warrants urgent vascular assessment.
Reading your report
An AAA screening report can look intimidating. It isn’t.
Whatever the finding, the report keeps to the same four parts.
A quiet reminder
The report is written for your doctor, not for you — and that’s normal.
If you would like us to talk you through it before your follow-up, just ask.
- 01 Header
Indication and risk factors
Your details, the reason for screening, and vascular risk factors — age, sex, smoking status, family history — that shape interpretation.
- 02 Technique
Probe and measurement method
The curvilinear probe used, and confirmation that measurements were taken in transverse and longitudinal planes.
- 03 Findings
Aortic diameter and adjacent vessels
The maximum aortic diameter, plaque or thrombus within the sac, and comment on the iliac arteries.
- 04 Impression
The conclusion: read this first
Normal, small, medium or large aneurysm — and the concrete next step (reassurance, surveillance interval or vascular referral).
Frequently asked
Everything patients ask about AAA screening.
Quick answers on who is screened, what to expect on the day, size bands, and when to worry.
-
What is abdominal aortic aneurysm screening?
A one-off ultrasound scan of the abdominal aorta — the main artery running from the chest to the pelvis. It measures the aorta’s diameter to detect an aneurysm (a diameter of 3 cm or more) before it can rupture.
-
Who is offered AAA screening on the NHS?
The NHS AAA Screening Programme invites men in the year they turn 65. Men over 65 who missed the invitation can self-refer through their local screening service. Women and higher-risk adults can access screening privately.
-
Does the scan hurt, and do I need to prepare?
It is painless — a warm gel is applied to the abdomen and a handheld ultrasound probe is swept across it for ten to fifteen minutes. Most protocols require no fasting; wear something loose and comfortable so the abdomen is easy to expose.
-
What happens if the scan finds an aneurysm?
It depends on the size. Small aneurysms (3.0–4.4 cm) are followed with annual ultrasound; medium (4.5–5.4 cm) with three-monthly scans; large (≥ 5.5 cm) or those growing faster than 1 cm per year are referred to vascular surgery for repair discussion.
-
Should women or younger adults be screened?
The NHS does not routinely screen women, but private screening is available for women with a family history of AAA, and for younger adults with strong cardiovascular risk factors or connective-tissue disease. We can arrange this.
-
When is AAA a medical emergency?
Sudden severe abdominal or back pain — particularly with collapse, sweating or a pulsatile mass — may indicate rupture, which is a surgical emergency. Call 999 immediately; do not wait for a private appointment.
Sources
Where this guide comes from.
- NHS Abdominal Aortic Aneurysm Screening Programme.
- NICE. Abdominal aortic aneurysm: diagnosis and management (NG156).
- European Society for Vascular Surgery. Clinical practice guidelines on the management of abdominal aorto-iliac artery aneurysms.
- Society for Vascular Surgery. Practice guidelines on the care of patients with an abdominal aortic aneurysm.
Reviewed by Pulse Atlas Editorial Board (). Last reviewed 2026-07-30. Next review 2027-07-30.
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In practice, in London
Where abdominal aortic aneurysm screening sits in a private London pathway
With abdominal aortic aneurysm screening, the London question is usually about report turnaround and the radiologist reading it — not whether the scan is available. On the NHS, abdominal aortic aneurysm screening typically sits behind a triage step and a wait that can stretch from a few weeks into months. In London’s private sector, the same appointment often lands within days. That speed matters when symptoms are disrupting work, sleep, or a plan you’d already committed to — and it’s the single most common reason people call us in the first place.
A typical private booking for abdominal aortic aneurysm screening in London starts with a consultant conversation — sometimes in person on Harley Street or Marylebone, sometimes on video if that suits better. Any imaging or diagnostics happen at a nearby CQC-registered facility, and reports usually land within 24 to 72 hours. The whole loop, from first call to written report, is often done inside a fortnight. For abdominal aortic aneurysm screening specifically, the difference between a routine report and a sub-speciality read is where private care earns its keep.
The value of going through a concierge for abdominal aortic aneurysm screening isn’t access — anyone with an insurer or a credit card can get a private appointment in London. The value is knowing which consultant reads this particular presentation best, which unit turns reports around fastest, and which pathway won’t hit a dead end if the findings point somewhere unexpected.