The carotid arteries run up each side of the neck. Each common carotid divides into internal and external branches: the internal branch helps supply the brain and eye, while the external branch supplies structures of the face and head. Atherosclerosis is a build-up of plaque in an artery wall. Plaque often develops near this branch point and can narrow the internal carotid, a finding called carotid stenosis.

Plaque can disrupt the artery lining. Clot or small fragments may break away and travel to a smaller artery in the brain or eye, blocking blood flow. Severe narrowing can also reduce flow. A shortage of oxygen and glucose can damage brain tissue: an ischaemic stroke is caused by interrupted blood supply, while a TIA is a temporary interruption producing stroke-like symptoms. Bleeding in the brain is another cause of stroke, with different treatment; not every stroke or TIA is caused by the carotid arteries.

Narrowing commonly causes no warning symptoms. When it has caused a recent TIA or non-disabling stroke in the territory supplied by that artery, clinicians call it symptomatic carotid stenosis. Temporary loss of sight in one eye, sometimes described as a curtain coming down, can be a warning sign. Asymptomatic means there has not been a relevant recent stroke or TIA linked to that artery, not that a scan result can safely be ignored.

A clinician asks what happened, which side or eye was affected, when symptoms began and ended, and whether they have returned. They examine strength, sensation, speech and vision. Blood pressure, blood tests for cholesterol and diabetes, and an electrocardiogram or heart rhythm monitoring can help identify other contributors, including atrial fibrillation. A narrowing on a scan does not by itself prove it caused the episode.

Carotid duplex ultrasound uses sound waves and blood-flow measurements to assess narrowing. CT angiography or MR angiography may provide additional detail about the neck and head arteries when needed. Brain imaging helps distinguish bleeding, established injury and other causes; acute suspected stroke and fully resolved suspected TIA have different imaging pathways. NICE recommends urgent carotid imaging for people with TIA whom a specialist considers candidates for endarterectomy.

A stenosis percentage depends on how it is measured. NICE specifies NASCET and ECST criteria, which use different reference measurements and cannot be interchanged as though their percentages mean the same thing. Ask which artery and side is involved, how severe it is, which measurement method was used, and whether the findings match the symptoms. Near-occlusion, where the artery beyond the narrowing has collapsed, and a completely blocked artery require a different specialist assessment from an ordinary narrowing.

After a recent non-disabling stroke or TIA caused by a narrowed carotid artery, the risk of another stroke can be highest early. NICE recommends urgent assessment and referral for endarterectomy in people with stable neurological symptoms and symptomatic narrowing of 50–99% by NASCET, or 70–99% by ECST, alongside best medical treatment. These figures apply to that specified population and measurement method; they do not mean everyone with that scan percentage should have an operation.

The National Clinical Guideline for Stroke recommends endarterectomy as soon as possible within seven days of onset for people with TIA or acute non-disabling ischaemic stroke, stable neurological symptoms and symptomatic stenosis of 50–99% by NASCET, taking account of clinical circumstances. Urgent referral does not mean every operation is safe immediately: the stroke team and vascular team assess the severity of the stroke, brain imaging, stability, bleeding risk, other illnesses and anaesthetic risk. Ask what timing is recommended in your case and what to do if symptoms recur while waiting.

A Cochrane review pooled older randomised trials comparing endarterectomy plus medical care with medical care alone in people with recently symptomatic narrowing. Surgery offered greater stroke-prevention benefit in selected people with severe stenosis without near-occlusion than in those with moderate narrowing; it was not beneficial for mild stenosis. Trial participants were mostly men, and medical treatment and patient selection have changed. Age, sex, timing, operative risk, scan findings and other conditions affect the likely balance for an individual.

When narrowing is asymptomatic, the immediate risk after an intervention must be weighed against the risk of future stroke with intensive medical treatment alone. The degree of narrowing, other vascular risk factors, life expectancy, individual health, local operator outcomes and personal priorities matter. Treatment of risk factors remains important whether or not a procedure is chosen. Ask whether monitoring and medical therapy alone are reasonable for you and what evidence supports adding a procedure.

Medical treatment aims to reduce the risk of a future stroke and other vascular events. Depending on the cause and your health, it can include an antiplatelet such as aspirin or clopidogrel, a statin or other cholesterol-lowering treatment, and treatment for high blood pressure or diabetes. Atrial fibrillation may call for an anticoagulant instead of or in addition to another treatment in selected circumstances. A clinician chooses the combination and duration because bleeding risk and the reason for treatment vary.

Endarterectomy opens the neck artery and removes plaque directly. Carotid artery stenting usually approaches the narrowing with a catheter through an artery, often in the groin, uses a balloon and leaves a small mesh tube to hold the vessel open. Stenting may avoid a neck incision but can release material into the circulation; protection devices are sometimes used. Both procedures carry stroke risk, and both require ongoing medical prevention. Prior neck surgery or radiotherapy, anatomy, age, other health problems and local expertise can influence the choice.

Stenting also carries risks of access-site bleeding, artery injury, contrast reaction or kidney problems, a slow heart rate, and later re-narrowing. Antiplatelet treatment around a stent is important to reduce clotting; the medicines and duration are chosen for the individual, and sometimes two antiplatelets are prescribed together. Ask your specialist how these risks and medicine requirements compare with surgery in your case, and do not stop prescribed treatment without advice.

In the International Carotid Stenting Study, 1,713 selected adults over 40 with symptomatic carotid narrowing who were considered suitable for either treatment were randomly assigned to stenting or endarterectomy. At five years, estimated risk of any stroke was 15.2% with stenting and 9.4% with surgery; the study found no statistically significant difference in fatal or disabling stroke. These are trial-group estimates, not personal predictions. The procedures and medical care have evolved, and patients with major stroke or unsuitable anatomy were excluded.

CREST-2 ran two separate randomised trials in people with high-grade asymptomatic narrowing: 1,245 were assigned to stenting plus intensive medical management or medical management alone, and 1,240 to endarterectomy plus medical management or medical management alone. At four years, the measured composite of any stroke or death within 44 days of randomisation and later ischaemic stroke on the side of the studied artery was 2.8% versus 6.0% in the stenting trial, and 3.7% versus 5.3% in the surgery trial; the surgery difference was not statistically significant. The trials did not directly compare stenting with surgery, and a non-significant result does not establish that surgery benefits no individual. Eligibility, follow-up, operators and treatments affect how results apply.

Ask your team to compare the expected risk of stroke with medical therapy alone and the immediate and longer-term risks with each suitable procedure, using the same time period. Ask how the experience and outcomes of the local service affect the estimate, and whether an alternative is suitable for your anatomy and health. You can discuss the benefits, risks and alternatives before deciding wherever time and circumstances allow.

Pre-assessment may include a review of your symptoms, scans, heart and lung health, other conditions, previous anaesthetics and allergies, with blood tests or an ECG as needed. Tell the team about previous neck operations, difficulties swallowing or speaking, and any new symptoms. Bring a list of prescription and non-prescription medicines, vitamins and herbal products.

Ask specifically which medicines to take, pause or restart and when, including antiplatelets, anticoagulants and diabetes treatments. The instructions depend on the medicine and your circumstances. Do not stop a blood-thinning medicine independently. Your hospital will give fasting instructions for food and drink, and may discuss local or general anaesthesia. Arrange a lift and help at home if needed; urgent surgery may leave little time for advance planning.

If you develop a new illness while waiting, contact the team for advice. New or recurrent stroke signs are an emergency: call 999 rather than waiting for the appointment. Ask what the plan is if your surgery date changes, and whom to contact during the day and out of hours.

An anaesthetist discusses general anaesthetic, under which you are asleep, or local or regional anaesthetic, under which the neck is numbed and you are awake, sometimes with sedation. The team monitors heart rhythm, blood pressure and neurological function. When awake, you may be asked to speak or move during the procedure. The approach is chosen with your team; neither choice is right for everyone.

The surgeon makes an incision on the side of the neck, exposes the artery and temporarily clamps it. A temporary shunt, a small tube that carries blood past the clamped segment, may be used if needed. The surgeon opens the artery and removes the plaque. The opening is stitched closed, sometimes with a patch to widen it and reduce the chance of re-narrowing. Clamps are removed and blood flow is restored.

The neck wound is closed with stitches or clips; a small drain may be left temporarily to remove excess blood. NHS England says the procedure usually takes one to two hours. Afterwards the team checks blood pressure, pulse, the wound and movements of the face, arms and legs. The operation is intended to lower future stroke risk; it cannot undo damage from a stroke that has already occurred.

Surgery itself can cause a stroke or TIA, including from clot or debris, and can occasionally cause death. Heart attack, bleeding, wound infection and anaesthetic complications are also possible. Blood pressure can rise or fall after treatment and is monitored. Ask for the team’s estimate of your own procedural stroke, heart attack and death risks, and how these compare with your risk without an operation.

Bleeding into the neck may form a haematoma and occasionally require urgent further surgery. Nearby nerves can be affected: numbness around the scar, facial weakness, a hoarse voice, or difficulty moving the tongue or swallowing can occur. Many nerve problems improve, but some persist. Tell the team about new or worsening swallowing, voice or facial changes; use the emergency instructions above for breathing difficulty or rapidly growing neck swelling.

The artery can narrow again after an initially successful operation. Carotid surgery lowers risk for selected people but does not eliminate future stroke risk or treat every possible cause of stroke. Ask whether you need a repeat ultrasound or clinic appointment, what symptoms need action, and how ongoing vascular prevention will be coordinated.

Most people are monitored overnight and can leave the next day if well enough, though a stroke, other conditions or complications can mean a longer stay. Neck soreness, bruising and some swelling can be expected initially, and tiredness may last weeks. Check that you can eat and drink safely, understand your medicines and have written wound-care and emergency contact instructions before discharge.

Rest and build activity gradually; gentle walking is often encouraged. NHS England advises avoiding heavy lifting for at least six weeks and strenuous activity for about six weeks. Follow the wound-washing instructions from your own team and ask about stitches or clips, return to work, exercise and sex. If you have also had a stroke, rehabilitation for movement, speech, swallowing, thinking or fatigue may follow a different and longer timetable than wound healing.

Take prevention medicines as prescribed and ask your GP, pharmacist or specialist for help with side effects, missed doses or repeat supplies. Do not stop an antiplatelet or anticoagulant on your own. Discuss blood pressure, cholesterol, diabetes management, smoking cessation, food and physical activity. A follow-up appointment may review healing and symptoms; ultrasound surveillance is individual, so ask whether and when you need a scan.

In Great Britain, DVLA guidance says Group 1 car and motorcycle drivers must not drive for at least one month after a stroke or TIA. Driving after stroke can resume after one month only if clinical recovery is satisfactory; DVLA must be notified if relevant neurological problems persist at one month, including visual field, cognitive or limb impairment, with specific exceptions. A separate month off driving follows each TIA. Other rules, including for seizures or vision, may apply. Ask your clinician if you are unsure and check the current guidance.

For Group 2 bus and lorry licences in Great Britain, a driver must stop driving and notify DVLA after stroke or TIA; the licence is refused or revoked for one year. Relicensing after a year may be considered if the medical conditions are met. DVLA also requires Group 2 drivers with carotid stenosis to notify it and not drive unless an appropriate healthcare professional considers it safe. Some drivers need further cardiac testing. Check the detailed rules for your circumstances.

Northern Ireland drivers should check with the DVA. NI Direct says it must be contacted in specified circumstances, including residual problems a month after stroke and holding an LGV or PCV licence. Ask your clinician and DVA for the rules that apply to your own licence. Following neck surgery, NHS England advises not driving until your neck is free of pain and you can look over your shoulder; this can take around four to six weeks. Stroke or TIA restrictions may last longer than surgical recovery. Check with your insurer before returning to driving.