Skip to main content

Health condition

Carotid artery stenosis, graded on duplex, treated by MDT.

A major cause of ischaemic stroke, and a very treatable one. Best medical therapy for everyone, with carotid endarterectomy or stenting for the right symptomatic patients.

Jump to treatment
A radiographer guides a patient onto the bed of an advanced 3 Tesla MRI scanner in a London imaging suite

Why trust this guide

  • 01

    Editorial team

    Written by our editorial team from the UK sources listed on each page.

  • 02

    Sourced from guidance

    Checked against NICE, ESO and AHA sources you can see at the end.

  • 03

    Current for 2026

    Reflects modern UK vascular practice including duplex-first assessment, high-intensity statins and stroke-team pathways.

Key facts

Carotid stenosis at a glance.

The essentials, in plain English: what it is, how it is graded, and how UK vascular teams treat it today.

  • What it is

    Atherosclerotic narrowing of the internal carotid artery, one of the main pipes carrying blood to the brain.

  • Why it matters

    Carotid disease drives roughly 15 to 20 percent of ischaemic strokes in the UK.

  • How it is graded

    By NASCET or ECST measurement: mild under 50 percent, moderate 50 to 69 percent, severe 70 to 99 percent, occlusion 100 percent.

  • How it presents

    Often silently, sometimes as TIA or amaurosis fugax, sometimes as a full ischaemic stroke.

  • First-line test

    Carotid duplex ultrasound with peak systolic velocity and the ICA to CCA ratio.

  • Treatment ladder

    Best medical therapy for everyone, with carotid endarterectomy or stenting for the right symptomatic patients.

Why this guide matters

Best medical therapy first, revascularisation for the right patient.

Carotid disease is common and preventable, and the three points below shape everything else on this page.

  • Medical therapy is the foundation

    Antiplatelet, high-intensity statin and tight blood pressure control transform natural history, whatever else is planned.

  • Symptoms bring the strongest evidence

    Symptomatic 70 to 99 percent stenosis has clear evidence for carotid endarterectomy within 14 days, per NASCET.

  • Asymptomatic disease is nuanced

    Modern medical therapy has narrowed the benefit of surgery. Decisions belong in a shared, MDT-led conversation.

How the diagnosis is made

From first symptom to an MDT plan.

The steps a UK GP, TIA clinic or vascular team will normally follow, in order, so you know what to expect and why.

  1. 01

    Assessing

    History and neurological exam

    A structured account of any TIA symptoms, amaurosis fugax, weakness or speech disturbance, plus a full neurological examination.

  2. 02

    Assessing

    Cardiovascular risk profile

    Blood pressure, lipids, HbA1c, smoking status and family history to place the stenosis in a wider atherosclerosis picture.

  3. 03

    Assessing

    Auscultation for a bruit

    A carotid bruit is a soft clue, not a diagnosis, and often triggers the first duplex scan when found incidentally.

  4. 04

    Confirming

    Carotid duplex ultrasound

    The first-line test in the UK: peak systolic velocity, end-diastolic velocity and the ICA to CCA ratio grade the stenosis.

  5. 05

    Confirming

    CT angiogram to confirm

    Confirms the duplex result, maps the arch and neck vessels and helps the vascular team plan surgery or stenting.

  6. 06

    Planning

    MR angiogram if needed

    A useful alternative when contrast or radiation is a concern, and to look at intracranial vessels alongside the neck.

  7. 07

    Planning

    Vascular and stroke MDT

    Digital subtraction angiography is rarely needed. The plan is set by a joint vascular and stroke team, ideally within 14 days of symptoms.

Typical timeline: from TIA-clinic assessment to a definitive plan within 14 days.

Symptoms

What carotid stenosis actually looks like.

Often silent, sometimes a TIA, occasionally a stroke. And the features that mean it’s time to escalate right now.

  • Asymptomatic bruit

    Often the first sign, picked up on a routine examination or as an incidental imaging finding.

  • Amaurosis fugax

    A transient curtain of monocular blindness lasting minutes, caused by an embolus to the retinal artery.

  • Ischaemic stroke

    A sudden focal neurological deficit that persists: face, arm or leg weakness, speech disturbance or visual loss.

  • Cognitive change

    Slower thinking or word-finding difficulty from chronic hypoperfusion, especially with severe bilateral disease.

  • Coexisting vascular disease

    Angina, claudication or an abdominal aortic aneurysm often travel with carotid disease as part of a systemic pattern.

  • Silent progression

    Many patients feel entirely well until the day of a TIA or stroke, which is why risk-factor control matters early.

  • Red flag - suspected stroke or TIA

    Any sudden focal neurological symptom is a 999 call. Time-critical treatment saves brain and rules the following weeks.

Treatment

How carotid stenosis is treated in the UK.

Best medical therapy for everyone, with carotid endarterectomy the default revascularisation option and stenting reserved for the right anatomy.

  • Antiplatelet therapy

    Clopidogrel 75 mg daily, or aspirin with dipyridamole, to reduce the risk of a further embolic event.

  • High-intensity statin

    Atorvastatin 80 mg to stabilise plaque and lower LDL, alongside diet and lifestyle change.

  • Blood pressure control

    A target of under 130 over 80 in most patients, individualised in the very elderly and those with tight bilateral disease.

  • Diabetes and metabolic care

    HbA1c control with modern agents such as SGLT2 inhibitors and GLP-1 receptor agonists where indicated.

  • Smoking, weight and exercise

    Smoking cessation, dietary change, weight loss and regular activity are non-negotiable foundations.

  • Carotid endarterectomy (CEA)

    The evidenced procedure for symptomatic 70 to 99 percent stenosis, ideally within 14 days of symptoms.

  • Carotid artery stenting (CAS)

    An alternative to endarterectomy for high surgical-risk anatomy, delivered in specialist UK centres. See /treatments/carotid-artery-stenting/.

  • TCAR and MDT planning

    Transcarotid artery revascularisation with flow reversal is an emerging option. All decisions sit with a joint vascular and stroke MDT.

What this guide is based on

The sources behind every claim on this page.

UK national guidance, European stroke standards and the landmark carotid trials, current at the time of last review.

Key references

Guidelines and trials we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your GP, stroke physician or vascular surgeon knows your imaging and history, and can tell you which parts apply to you. If in doubt, get seen.

  • NICE. Stroke and transient ischaemic attack in over 16s (NG128).

  • European Stroke Organisation. Guideline on the management of extracranial carotid artery disease.

  • AHA/ASA. Guidelines for the primary and secondary prevention of stroke.

  • NASCET, ECST, ACST-1 and CREST-2 trial data on carotid revascularisation.

Red flags

When carotid disease needs urgent attention.

Most carotid disease is worked up electively. These are the situations that aren’t, and where the stroke or vascular team needs to see you today.

  • Suspected stroke - FAST symptoms

    Facial droop, arm weakness or speech difficulty is a 999 call. Thrombolysis and thrombectomy are strictly time-limited.

  • TIA in the last 7 days

    Any resolved focal neurological event needs same-day TIA-clinic assessment, imaging and antiplatelet therapy.

  • Amaurosis fugax

    Transient monocular visual loss is a retinal TIA and carries the same urgency as a hemispheric event.

  • Crescendo TIAs

    Repeated events in quick succession need urgent admission and expedited carotid imaging and revascularisation.

  • New neurological deficit after CEA/CAS

    Any fresh weakness, speech disturbance or visual loss after a procedure needs immediate vascular and stroke review.

  • Neck haematoma after surgery

    Swelling, bruising or airway concern after carotid endarterectomy is an emergency needing return to theatre.

  • Near-occlusion or occlusion

    Management is nuanced and controversial. It belongs in a specialist vascular and stroke MDT, not in primary care alone.

  • Coexisting AAA, CAD or PAD

    Atherosclerosis rarely sits in one bed. Screen and manage the whole vascular tree, not just the neck.

  • Rapidly progressive cognitive decline

    With severe bilateral carotid disease this may reflect hypoperfusion and deserves neurovascular review.

Living with it

A treatable disease, with a clear ladder.

Four things that make the biggest difference day to day: take the medical therapy seriously, learn FAST, sort the lifestyle basics, and keep your surveillance scans.

A quiet reminder

Consistency beats intensity, every time.

Small, steady habits kept up for years do more for your arteries than a heroic month that doesn’t last.

  1. 01 Foundation

    Take the medical therapy seriously

    Antiplatelet, statin and blood pressure control are the treatment. Surgery and stenting sit on top of them, not instead of them.

  2. 02 Symptoms

    Know your FAST symptoms

    Face, arm, speech and time. Any sudden focal neurological symptom is a 999 call, even if it resolves within minutes.

  3. 03 Lifestyle

    Stop smoking, move more, eat well

    Smoking cessation, a Mediterranean-style diet and regular activity change the natural history of the disease.

  4. 04 Follow-up

    Keep your surveillance scans

    Repeat duplex scans track progression and pick up restenosis after CEA or stenting. Don’t skip them.

Frequently asked

Everything we get asked about carotid stenosis.

Quick answers on grading, duplex, endarterectomy and stenting.

  • What is carotid artery stenosis?

    It is atherosclerotic narrowing of the internal carotid artery, one of the main arteries supplying blood to the brain. Plaque builds up over years and can either restrict flow or throw off small emboli that cause a TIA or stroke.

  • How is the severity graded?

    By the degree of luminal narrowing on imaging, using NASCET or ECST criteria. Mild is under 50 percent, moderate 50 to 69 percent, severe 70 to 99 percent, and total occlusion is 100 percent. The grade drives the treatment decision.

  • Which test comes first?

    Carotid duplex ultrasound is the first-line test in the UK. It uses peak systolic velocity, end-diastolic velocity and the ICA to CCA ratio to grade the stenosis. CT angiography confirms the result and helps plan surgery or stenting.

  • Do I need carotid endarterectomy?

    CEA is strongly indicated for symptomatic stenosis of 70 to 99 percent, ideally within 14 days of symptoms. In the 50 to 69 percent range the benefit is smaller and depends on age, sex and risk factors. Asymptomatic disease is more controversial as modern medical therapy has narrowed the CEA benefit.

  • What is carotid artery stenting?

    Carotid artery stenting is a catheter-based alternative to CEA, usually reserved for patients at high surgical risk, such as previous neck radiation, a high lesion, contralateral occlusion or redo surgery. It is delivered in specialist UK vascular centres.

  • Can I just take tablets and avoid surgery?

    For many patients with asymptomatic or mild disease, best medical therapy alone is the right answer. For symptomatic severe disease, medical therapy is essential but not enough on its own. The plan sits with a joint vascular and stroke MDT.

Related content

Keep reading.