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Overview

What Is Carotid Artery Stenosis?

Carotid artery stenosis is narrowing in one or both carotid arteries, the main neck arteries that carry blood to the brain. It usually develops when plaque made of cholesterol, fat and other materials builds up inside the artery wall. Narrowing can reduce blood flow to the brain, while plaque can also break apart and form a clot that travels to the brain. These events may cause a transient ischemic attack (TIA) or stroke.

Symptoms

Carotid Artery Stenosis Symptoms

Carotid artery stenosis often has no symptoms of its own. It may first become apparent when a TIA or stroke causes a sudden change in movement, speech, vision or alertness. These warning signs can happen even when the carotid artery blockage is not known in advance.

  • Sudden weakness or numbness on one side of the body.
  • Sudden trouble speaking or understanding speech (aphasia).
  • Sudden loss of vision in one eye (amaurosis fugax).
  • Sudden dizziness or loss of balance.
  • Sudden severe confusion.

Act now

Sudden symptoms may be a stroke warning

Call emergency services immediately for any sudden stroke-like symptom, even if it improves within minutes. A TIA can be a warning of a more serious stroke and requires urgent medical evaluation.

Causes

Causes of Carotid Artery Stenosis

Atherosclerosis is the usual cause of carotid artery disease. Cholesterol, fat, calcium and inflammatory material collect in the artery wall and form plaque. The plaque can narrow the passage, make the artery surface irregular or contribute to a blood clot that blocks blood flow to the brain. This process can affect the common carotid artery, the internal carotid artery or nearby carotid vessels in the neck.

  • Carotid artery dissection is a tear in the artery wall that can narrow the vessel or allow a clot to form.
  • Fibromuscular dysplasia is an abnormal growth in the artery wall that can create areas of narrowing.
  • Vasculitis, or inflammation of blood vessels, can damage and narrow a carotid artery.
  • Radiation-related arterial injury can cause scarring and narrowing years after treatment to the neck.
  • An injury to the neck can damage a carotid artery and lead to narrowing or clot formation.

Risk Factors

Risk Factors for Carotid Artery Stenosis

Nonmodifiable risk factors

  • Older age increases the chance that plaque will build up in the carotid arteries over time.
  • A family history of atherosclerosis or stroke may indicate inherited vascular risk.
  • A personal history of peripheral artery disease, coronary artery disease or stroke suggests a higher risk of carotid disease.

Modifiable or treatable risk factors

  • Smoking damages artery walls and accelerates plaque buildup; stopping tobacco use can lower vascular risk.
  • High blood pressure strains artery walls and can be treated with lifestyle changes and prescribed medicine.
  • High cholesterol promotes plaque formation and may improve with heart-healthy habits and cholesterol-lowering treatment.
  • Diabetes can damage blood vessels, so blood sugar management and medical care are important.
  • Obesity increases cardiovascular risk and may improve through nutrition, activity and clinical support.
  • Physical inactivity contributes to vascular risk; regular activity can help when it is safe for the individual.
  • An unhealthy diet can worsen blood pressure and cholesterol, while a heart-healthy eating pattern can help address both.

Complications

Complications of Carotid Artery Stenosis

The major complication is reduced blood flow to the brain or a clot formed from plaque traveling through the carotid artery. This can cause a transient ischemic attack or an ischemic stroke. A TIA may resolve without permanent injury, but it is an urgent warning that a disabling stroke could follow.

  • Recurrent transient ischemic attacks can signal continuing risk of a larger stroke.
  • A stroke can cause permanent weakness or paralysis, often affecting one side of the body.
  • Damage to brain areas controlling communication or vision can cause lasting speech or vision impairment.
  • A stroke may lead to cognitive effects, including problems with memory, attention or judgment.
  • Significant disability can result in loss of independence and a need for ongoing support.
  • A severe stroke can cause death.

Diagnosis

Diagnosis of Carotid Artery Stenosis

Evaluation includes a medical history, review of vascular risk factors and a neurologic examination. A clinician may listen over the neck for a bruit, an abnormal sound caused by turbulent blood flow, but a normal examination does not rule out carotid stenosis. Imaging is needed to confirm narrowing and assess its severity.

  • Carotid duplex ultrasound uses sound waves to measure blood flow and estimate narrowing without radiation.
  • CT angiography combines X-rays with contrast material to create detailed images of the carotid arteries and nearby blood vessels.
  • MR angiography uses magnetic resonance imaging to show blood vessels and may be performed with or without contrast.
  • Catheter-based cerebral angiography maps the arteries in detail and may be used when more precise information is needed for treatment planning.

Treatment & Management

Treatment and Management

Management is individualized according to symptoms, the degree of stenosis, life expectancy, surgical risk and other health conditions. The central goal is to prevent stroke and reduce the progression of carotid artery blockage. Some people need medical treatment and monitoring alone, while selected patients may benefit from a procedure to improve blood flow.

  • Stopping tobacco use reduces damage to the carotid arteries and lowers overall cardiovascular risk.
  • Heart-healthy eating and regular physical activity support healthy blood pressure, cholesterol and weight.
  • Blood pressure control through lifestyle measures and prescribed medicine helps protect artery walls.
  • Cholesterol-lowering therapy may reduce plaque-related cardiovascular risk when prescribed.
  • Diabetes management helps limit blood vessel damage and may include changes to food, activity and medication.
  • Antiplatelet medication may be prescribed to reduce clot-related risk; take it only as directed by a clinician.

Procedures for selected patients

ProcedureWhat it involvesWhen it may be consideredKey considerations
Carotid endarterectomyA surgeon opens the carotid artery and removes plaque from its inner wall to restore a wider channel for blood flow.It may be considered for selected people with significant narrowing, particularly when symptoms have occurred and surgical risk is acceptable.It is carotid artery surgery with risks such as stroke, heart attack, nerve injury or bleeding; benefits must be weighed against individual risk.
Carotid artery stentingA catheter is used to place a small mesh tube, or stent, that supports the artery and improves its passage.It may be considered when revascularization is appropriate but surgery carries higher risk or an anatomic factor makes stenting preferable.There is a risk of clot or stroke during the procedure, and the choice depends on anatomy, age, health and specialist assessment.

Prevention

Preventing Carotid Artery Stenosis and Stroke

  • Do not smoke, and seek help with quitting if needed.
  • Follow a heart-healthy eating pattern that limits excess saturated fat, salt and highly processed foods.
  • Stay physically active according to your health and a clinician’s advice.
  • Maintain a healthy weight or work toward gradual weight improvement with appropriate support.
  • Control blood pressure and diabetes through regular monitoring and prescribed treatment.
  • Manage cholesterol with lifestyle measures and medication when recommended.
  • Take prescribed medicines consistently and discuss side effects rather than stopping them on your own.

Outlook and Prognosis

Outlook and Prognosis

Carotid artery stenosis can remain stable when treatment and risk-factor control are effective, but progression and stroke risk vary. Important influences include the degree of narrowing, whether symptoms have occurred, plaque behavior and other vascular disease. Regular follow-up helps clinicians adjust treatment as a person’s risk changes.

  • A previous TIA or stroke generally indicates a higher risk than narrowing found without symptoms.
  • The response to medical therapy helps show whether risk factors are being controlled.
  • Good blood pressure and cholesterol control can reduce ongoing stress on the arteries.
  • Not smoking supports healthier blood vessels and lowers the chance of future vascular events.
  • Diabetes management is important because uncontrolled blood sugar can damage blood vessels.
  • Follow-up imaging, when recommended, can show whether the narrowing is stable or changing.

When Should You See a Doctor

When Should You See a Doctor?

Call emergency services

Possible stroke or transient ischemic attack

Call emergency services immediately for sudden facial drooping, one-sided weakness or numbness, speech difficulty, sudden vision loss, severe dizziness, loss of balance or confusion—even if the symptoms resolve. Do not drive yourself or wait to see whether symptoms return.

  • Contact a clinician about a new neck bruit found during an examination.
  • Arrange medical evaluation if you have a history of TIA or stroke.
  • Discuss follow-up care if you have known carotid narrowing or carotid artery blockage.
  • Seek an appointment if you have multiple uncontrolled cardiovascular risk factors.

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