Carotid artery stenosis

What is carotid artery stenosis?

Carotid artery stenosis is the narrowing of the main arteries in your neck that carry oxygenated blood to the brain, most often caused by fatty plaque buildup.

Its severity is measured by how much the blood vessel is blocked:

• Mild (<50%): low immediate stroke risk; signals a need for cardiovascular risk management.

• Moderate (50–69%): elevated stroke risk, especially if symptoms are present.

• Severe (70–99%): high stroke risk that often requires surgical intervention.

• Near-occlusion or occlusion (99–100%): extremely narrow or fully blocked, requiring specialist care.

Key distinction: Symptomatic stenosis (which has already triggered a mini-stroke/TIA or stroke) carries a far higher immediate risk than asymptomatic narrowing of the same degree, requiring urgent treatment.

Symptoms of carotid artery stenosis

Carotid stenosis is often completely silent until a major event occurs. Symptoms, when present, reflect reduced blood flow to the brain:

• Asymptomatic: causes no symptoms and is typically discovered incidentally during neck imaging or when a doctor hears an abnormal blood flow sound (bruit) with a stethoscope.

• TIA (mini-stroke): sudden neurological symptoms such as one-sided weakness or numbness, speech disturbance, or temporary loss of vision in one eye that resolve, without persistent neurological deficit. A TIA is a medical emergency because it can precede an ischaemic stroke.

• Ischaemic stroke: similar neurological symptoms to TIA caused by interruption of blood flow to part of the brain, resulting in persistent neurological injury or an area of acute brain infarction.

Important: Any sudden neurological symptom, such as facial weakness, arm weakness, speech difficulty, or visual loss, requires immediate emergency assessment using the FAST (Face, Arms, Speech, Time) framework. Do not wait for symptoms to resolve. Call emergency services immediately.

What causes carotid artery stenosis?

Carotid stenosis results from atherosclerosis, the same systemic inflammatory and metabolic process that causes coronary artery disease and peripheral arterial disease. Contributing causes include:

• Hypertension is the single most important risk factor, causing mechanical stress on the carotid bifurcation where flow turbulence is greatest and plaque formation most likely

• Dyslipidaemia elevated LDL, elevated ApoB, and elevated Lp(a) drive atherosclerotic plaque formation in the carotid wall

• Smoking causes direct endothelial injury, promotes thrombosis, and accelerates carotid atherosclerosis

• Diabetes and insulin resistance accelerate vascular endothelial dysfunction and carotid intima-media thickening

• Age carotid atherosclerosis accumulates progressively, with prevalence of significant stenosis rising sharply after 65

• Male sex men develop carotid atherosclerosis earlier than women, though post-menopausal women rapidly approach similar risk levels

• Chronic inflammation elevated CRP reflects systemic vascular inflammation promoting plaque instability

• Metabolic syndrome the combination of hypertension, dyslipidaemia, insulin resistance, and central obesity creates a self-reinforcing cycle of vascular risk

• Genetic factors familial hypercholesterolaemia and other inherited lipid disorders significantly accelerate carotid atherosclerosis

How is carotid artery stenosis detected?

Carotid artery stenosis is detected through neck imaging and a comprehensive vascular risk blood panel.

Neck MRI Elfcare's full body MRI covers the neck soft tissues as standard, and can identify carotid artery wall thickening, atherosclerotic plaque, and luminal narrowing as part of routine imaging. Duplex ultrasound remains the standard first-line tool for grading stenosis severity, but MRI does have one genuine advantage worth noting. MRI can characterise plaque composition, including intraplaque haemorrhage and lipid-rich necrotic core, features linked to instability and stroke risk independent of the stenosis percentage.

Blood tests Elfcare's panel includes markers that can provide information about several important cardiovascular and metabolic risk factors associated with atherosclerotic disease. These include:

• Total cholesterol, LDL, HDL, and triglycerides the primary lipid drivers of carotid atherosclerotic plaque formation

• ApoB a more precise measure of atherogenic particle burden than LDL alone

• Lipoprotein(a) an independent genetic risk factor for carotid atherosclerosis and stroke, unresponsive to standard statin therapy

• HbA1c and fasting glucose diabetes and insulin resistance accelerate carotid intima-media thickening and plaque formation

• CRP elevated systemic vascular inflammation promotes plaque instability and rupture risk

• Homocysteine elevated levels are independently associated with carotid atherosclerosis and stroke risk

• Creatinine and eGFR kidney disease is closely linked to vascular disease through shared risk mechanisms

• TSH thyroid dysfunction, particularly hypothyroidism, worsens lipid profile and cardiovascular risk

• Full blood count and haemoglobin anaemia and polycythaemia both affect cerebral oxygen delivery and stroke risk

Why early detection matters

Carotid artery stenosis is a narrowing of the carotid arteries supplying the brain, most often caused by atherosclerotic plaque. It can remain asymptomatic, but symptomatic stenosis can increase the risk of TIA or ischaemic stroke and may require urgent specialist assessment.

When significant or symptomatic carotid stenosis is identified, timely specialist assessment is important because treatment decisions can be time-sensitive. Depending on the degree of narrowing, symptoms, overall health and other risk factors, management may include medical treatment and, in selected patients, procedures such as carotid endarterectomy or carotid artery stenting.

Early identification of cardiovascular risk factors, including LDL cholesterol, lipoprotein(a), blood pressure and blood glucose, allows appropriate lifestyle and medical interventions to be considered. The aim is to reduce the risk of stroke and other cardiovascular events and to slow the progression of atherosclerotic disease.

How Elfcare can help

Elfcare's full body MRI includes imaging of the neck and brain as part of the examination. Where the carotid arteries are adequately visualised, MRI may identify structural vascular findings that warrant further assessment. Brain imaging can also identify previous infarcts or other structural findings that may provide additional clinical context. Because dedicated carotid imaging such as duplex ultrasound, CT angiography (CTA) or MR angiography (MRA) may be required to accurately assess the degree and clinical significance of carotid artery narrowing, further vascular imaging may be recommended when appropriate.

Our blood panel includes cardiovascular and metabolic markers such as LDL cholesterol, ApoB, Lp(a), HbA1c and CRP, which can help assess important risk factors associated with atherosclerotic disease.

If our MRI or blood tests identify findings that require further assessment, we help guide you toward appropriate follow-up or specialist care.