Carotid Artery Disease

What Is

Carotid artery disease is a disease in which a waxy substance called plaque builds up inside the carotid arteries. You have two common carotid arteries, one on each side of your neck. They each divide into internal and external carotid arteries.

The internal carotid arteries supply oxygen-rich blood to your brain. The external carotid arteries supply oxygen-rich blood to your face, scalp, and neck.

Carotid Arteries

Carotid artery disease diagram.
Figure A shows the location of the right carotid artery in the head and neck. Figure B shows the inside of a normal carotid artery that has normal blood flow. Figure C show the inside of a carotid artery that has plaque buildup and reduced blood flow.

Carotid artery disease is serious because it can cause a stroke, also called a “brain attack.” A stroke occurs if blood flow to your brain is cut off.

If blood flow is cut off for more than a few minutes, the cells in your brain start to die. This impairs the parts of the body that the brain cells control. A stroke can cause lasting brain damage; long-term disability, such as vision or speech problems or paralysis (an inability to move); or death.

Overview

Carotid artery disease is a major cause of stroke in the United States. Over time, plaque hardens and narrows the arteries. This may limit the flow of oxygen-rich blood to your organs and other parts of your body.

Atherosclerosis can affect any artery in the body. For example, if plaque builds up in the coronary (heart) arteries, a heart attack can occur. If plaque builds up in the carotid arteries, a stroke can occur.

A stroke also can occur if blood clots form in the carotid arteries. This can happen if the plaque in an artery cracks or ruptures. Blood cell fragments called platelets (PLATE-lets) stick to the site of the injury and may clump together to form blood clots. Blood clots can partly or fully block a carotid artery.

A piece of plaque or a blood clot also can break away from the wall of the carotid artery. The plaque or clot can travel through the bloodstream and get stuck in one of the brain's smaller arteries. This can block blood flow in the artery and cause a stroke.

Carotid artery disease may not cause signs or symptoms until the carotid arteries are severely narrowed or blocked. For some people, a stroke is the first sign of the disease.

Outlook

Carotid artery disease is a major cause of stroke in the United States. Other conditions, such as certain heart problems and bleeding in the brain, also can cause strokes. Lifestyle changes, medicines, and medical procedures can help prevent or treat carotid artery disease and may reduce the risk of stroke.

If you think you're having a stroke, you need urgent treatment. Call 9–1–1 right away if you have symptoms of a stroke. Do not drive yourself to the hospital. You have the best chance for full recovery if treatment to open a blocked artery is given within 4 hours of symptom onset. The sooner treatment occurs, the better your chances of recovery.

Causes

Carotid artery disease seems to start when damage occurs to the inner layers of the carotid arteries. Major factors that contribute to damage include:

When damage occurs, your body starts a healing process. The healing may cause plaque to build up where the arteries are damaged.

The plaque in an artery can crack or rupture. If this happens, blood cell fragments called platelets will stick to the site of the injury and may clump together to form blood clots.  

The buildup of plaque or blood clots can severely narrow or block the carotid arteries. This limits the flow of oxygen-rich blood to your brain, which can cause a stroke.

Risk Factors

The major risk factors for carotid artery disease, listed below, also are the major risk factors for coronary heart disease (also called coronary artery disease) and peripheral artery disease.

  • Diabetes. With this disease, the body’s blood sugar level is too high because the body doesn’t make enough insulin or doesn’t use its insulin properly. People who have diabetes are four times more likely to have carotid artery disease than are people who don’t have diabetes.
  • Family history of atherosclerosis. People who have a family history of atherosclerosis are more likely to develop carotid artery disease.
  • High blood pressure (Hypertension). Blood pressure is considered high if it stays at or above 140/90 mmHg over time. If you have diabetes or chronic kidney disease, high blood pressure is defined as 130/80 mmHg or higher. (The mmHg is millimeters of mercury—the units used to measure blood pressure.)
  • Lack of physical activity. Too much sitting (sedentary lifestyle) and a lack of aerobic activity can worsen other risk factors for carotid artery disease, such as unhealthy blood cholesterol levels, high blood pressure, diabetes, and overweight or obesity.
  • Metabolic syndrome. Metabolic syndrome is the name for a group of risk factors that raise your risk for stroke and other health problems, such as diabetes and heart disease. The five metabolic risk factors are a large waistline (abdominal obesity), a high triglyceride level (a type of fat found in the blood), a low HDL cholesterol level, high blood pressure, and high blood sugar. Metabolic syndrome is diagnosed if you have at least three of these metabolic risk factors.
  • Older age. As you age, your risk for atherosclerosis increases. The process of atherosclerosis begins in youth and typically progresses over many decades before diseases develop.
  • Overweight or obesity. The terms “overweight” and “obesity” refer to body weight that’s greater than what is considered healthy for a certain height.
  • Smoking. Smoking can damage and tighten blood vessels, lead to unhealthy cholesterol levels, and raise blood pressure. Smoking also can limit how much oxygen reaches the body’s tissues.
  • Unhealthy blood cholesterol levels. This includes high LDL (“bad”) cholesterol) and low HDL (“good”) cholesterol.
  • Unhealthy diet. An unhealthy diet can raise your risk for carotid artery disease. Foods that are high in saturated and trans fats, cholesterol, sodium, and sugar can worsen other risk factors for carotid artery disease.

Having any of these risk factors does not guarantee that you’ll develop carotid artery disease. However, if you know that you have one or more risk factors, you can take steps to help prevent or delay the disease.

If you have plaque buildup in your carotid arteries, you also may have plaque buildup in other arteries. People who have carotid artery disease also are at increased risk for coronary heart disease.

Screening and Prevention

Taking action to control your risk factors can help prevent or delay carotid artery disease and stroke. Your risk for carotid artery disease increases with the number of risk factors you have.

One step you can take is to make heart-healthy lifestyle changes, which can include:

Other steps that can prevent or delay carotid artery disease include knowing your family history of carotid artery disease. If you or someone in your family has carotid artery disease, be sure to tell your doctor.

If lifestyle changes aren’t enough, your doctor may prescribe medicines to control your carotid artery disease risk factors. Take all of your medicines as your doctor advises.

Signs, Symptoms, and Complications

Carotid artery disease may not cause signs or symptoms until it severely narrows or blocks a carotid artery. Signs and symptoms may include a bruit, a transient ischemic attack (TIA), or a stroke.

Bruit

During a physical exam, your doctor may listen to your carotid arteries with a stethoscope. He or she may hear a whooshing sound called a bruit. This sound may suggest changed or reduced blood flow due to plaque buildup. To find out more, your doctor may recommend tests.

Not all people who have carotid artery disease have bruits.

Transient Ischemic Attack (Mini-Stroke)

For some people, having a transient ischemic attack (TIA), or “mini-stroke,” is the first sign of carotid artery disease. During a mini-stroke, you may have some or all of the symptoms of a stroke. However, the symptoms usually go away on their own within 24 hours.

Stroke and mini-stroke symptoms may include:

  • A sudden, severe headache with no known cause
  • Dizziness or loss of balance
  • Inability to move one or more of your limbs
  • Sudden trouble seeing in one or both eyes
  • Sudden weakness or numbness in the face or limbs, often on just one side of the body
  • Trouble speaking or understanding speech

Even if the symptoms stop quickly, call 9–1–1 for emergency help. Do not drive yourself to the hospital. It’s important to get checked and to get treatment started as soon as possible.

A mini-stroke is a warning sign that you’re at high risk of having a stroke. You shouldn’t ignore these symptoms. Getting medical care can help find possible causes of a mini-stroke and help you manage risk factors. These actions might prevent a future stroke.

Although a mini-stroke may warn of a stroke, it doesn’t predict when a stroke will happen. A stroke may occur days, weeks, or even months after a mini-stroke.

Stroke

The symptoms of a stroke are the same as those of a mini-stroke, but the results are not. A stroke can cause lasting brain damage; long-term disability, such as vision or speech problems or paralysis (an inability to move); or death. Most people who have strokes have not previously had warning mini-strokes.

Getting treatment for a stroke right away is very important. You have the best chance for full recovery if treatment to open a blocked artery is given within 4 hours of symptom onset. The sooner treatment occurs, the better your chances of recovery.

Call 9–1–1 for emergency help as soon as symptoms occur. Do not drive yourself to the hospital. It’s very important to get checked and to get treatment started as soon as possible.

Make those close to you aware of stroke symptoms and the need for urgent action. Learning the signs and symptoms of a stroke will allow you to help yourself or someone close to you lower the risk of brain damage or death due to a stroke.

Diagnosis

Your doctor will diagnose carotid artery disease based on your medical history, a physical exam, and test results.

Medical History

Your doctor will find out whether you have any of the major risk factors for carotid artery disease. He or she also will ask whether you've had any signs or symptoms of a mini-stroke or stroke.

Physical Exam

To check your carotid arteries, your doctor will listen to them with a stethoscope. He or she will listen for a whooshing sound called a bruit. This sound may indicate changed or reduced blood flow due to plaque buildup. To find out more, your doctor may recommend tests.

Diagnostic Tests

The following tests are common for diagnosing carotid artery disease. If you have symptoms of a mini-stroke or stroke, your doctor may use other tests as well.

Carotid Ultrasound

Carotid ultrasound (also called sonography) is the most common test for diagnosing carotid artery disease. It's a painless, harmless test that uses sound waves to create pictures of the insides of your carotid arteries. This test can show whether plaque has narrowed your carotid arteries and how narrow they are.

A standard carotid ultrasound shows the structure of your carotid arteries. A Doppler carotid ultrasound shows how blood moves through your carotid arteries.

Carotid Angiography

Carotid angiography (an-jee-OG-ra-fee) is a special type of x ray. This test may be used if the ultrasound results are unclear or don't give your doctor enough information.

For this test, your doctor will inject a substance (called contrast dye) into a vein, most often in your leg. The dye travels to your carotid arteries and highlights them on x-ray pictures.

Magnetic Resonance Angiography

Magnetic resonance angiography (MRA) uses a large magnet and radio waves to take pictures of your carotid arteries. Your doctor can see these pictures on a computer screen.

For this test, your doctor may give you contrast dye to highlight your carotid arteries on the pictures.

Computed Tomography Angiography

Computed tomography (to-MOG-rah-fee) angiography, or CT angiography, takes x-ray pictures of the body from many angles. A computer combines the pictures into two- and three-dimensional images.

For this test, your doctor may give you contrast dye to highlight your carotid arteries on the pictures.

Treatment

Treatments for carotid artery disease may include heart-healthy lifestyle changes, medicines, and medical procedures. The goals of treatment are to stop the disease from getting worse and to prevent a stroke. Your treatment will depend on your symptoms, how severe the disease is, and your age and overall health.

Heart-Healthy Lifestyle Changes

Your doctor may recommend heart-healthy lifestyle changes if you have carotid artery disease. Heart-healthy lifestyle changes include:

Medicines

If you have a stroke caused by a blood clot, you may be given a clot-dissolving, or clot-busting, medication. This type of medication must be given within 4 hours of symptom onset. The sooner treatment occurs, the better your chances of recovery. If you think you’re having a stroke, call 9–1–1 right away for emergency care.

Medicines to prevent blood clots are the mainstay treatment for people who have carotid artery disease. They prevent platelets from clumping together and forming blood clots in your carotid arteries, which can lead to a stroke. Two common medications are:

  • Aspirin
  • Clopidogrel

Sometimes lifestyle changes alone aren’t enough to control your cholesterol levels. For example, you also may need statin medications to control or lower your cholesterol. By lowering your blood cholesterol level, you can decrease your chance of having a heart attack or stroke. Doctors usually prescribe statins for people who have:

  • Diabetes
  • Heart disease or have had a stroke
  • High LDL cholesterol levels

Doctors may discuss beginning statin treatment with those who have an elevated risk for developing heart disease or having a stroke.

You may need other medications to treat diseases and conditions that damage the carotid arteries. Your doctor also may prescribe medications to:

  • Lower your blood pressure.
  • Lower your blood sugar level.
  • Prevent blood clots from forming, which can lead to stroke.
  • Prevent or reduce inflammation.

Take all medicines regularly, as your doctor prescribes. Don’t change the amount of your medicine or skip a dose unless your doctor tells you to. Your health care team will help find a treatment plan that’s right for you.

Medical Procedures

You may need a medical procedure if you have symptoms caused by the narrowing of the carotid artery. Doctors use one of two methods to open narrowed or blocked carotid arteries: carotid endarterectomy and carotid artery angioplasty and stenting.

Carotid Endarterectomy

Carotid endarterectomy is mainly for people whose carotid arteries are blocked 50 percent or more.

For the procedure, a surgeon will make a cut in your neck to reach the narrowed or blocked carotid artery. Next, he or she will make a cut in the blocked part of the artery and remove the artery’s inner lining that is blocking the blood flow.

Finally, your surgeon will close the artery with stitches and stop any bleeding. He or she will then close the cut in your neck.

Carotid Endarterectomy

The illustration shows the process of carotid endarterectomy. Figure A shows a carotid artery with plaque buildup. The inset image shows a cross-section of the narrowed carotid artery. Figure B shows how the carotid artery is cut and how the plaque is removed. Figure C shows the artery stitched up and normal blood flow restored. The inset image shows a cross-section of the artery with plaque removed and normal blood flow restored.

Carotid Artery Angioplasty and Stenting

Doctors use a procedure called angioplasty to widen the carotid arteries and restore blood flow to the brain.

A thin tube with a deflated balloon on the end is threaded through a blood vessel in your neck to the narrowed or blocked carotid artery. Once in place, the balloon is inflated to push the plaque outward against the wall of the artery.

A stent (a small mesh tube) is then put in the artery to support the inner artery wall. The stent also helps prevent the artery from becoming narrowed or blocked again.

Carotid Artery Stenting

The illustration shows the process of carotid artery stenting. Figure A shows an internal carotid artery that has plaque buildup and reduced blood flow. The inset image shows a cross-section of the narrowed carotid artery. Figure B shows a stent being placed in the carotid artery to support the inner artery wall and keep the artery open. Figure C shows normal blood flow restored in the stent-widened artery. The inset image shows a cross-section of the stent-widened artery.

Living With

If you have carotid artery disease, you can take steps to manage the condition, reduce risk factors, and prevent complications. These steps include making heart-healthy lifestyle changes, following your treatment plan, and getting ongoing care.

Having carotid artery disease raises your risk of having a stroke. Know the warning signs of a stroke—such as weakness and trouble speaking—and what to do if they occur. Call 9–1–1 as soon as symptoms start (do not drive yourself to the hospital).

For more detailed information about the warning signs of a stroke, go to the section on warning signs below.

Treatment Plan

Following your treatment plan may help prevent your carotid artery disease from getting worse. It also can lower your risk for stroke and other health problems.

You may need to take medicines to control certain risk factors and to prevent blood clots that could cause a stroke. Taking prescribed medicines and following a healthy lifestyle can help control carotid artery disease. However, they don't cure the disease. You'll likely have to stick with your treatment plan for life.

Ongoing Care

If you have carotid artery disease, having ongoing medical care is important.

Most people who have the disease will need to have their blood pressure checked regularly and their blood sugar and blood cholesterol levels tested one or more times a year. If you have diabetes, you'll need routine blood sugar tests and other tests.

Testing shows whether these conditions are under control, or whether your doctor needs to adjust your treatment for better results.

If you've had a stroke or procedures to restore blood flow in your carotid arteries, you'll likely need a yearly carotid Doppler ultrasound test. This test shows how well blood flows through your carotid arteries.

Repeating this test over time will show whether the narrowing in your carotid arteries is getting worse. Results also can show how well procedures to treat your arteries have worked.

Follow up with your doctor regularly. The sooner your doctor spots problems, the sooner he or she can prescribe treatment.

Stroke Warning Signs

The signs and symptoms of stroke may include:

  • Sudden weakness or numbness in the face or limbs, often on only one side of the body
  • The inability to move one or more of your limbs
  • Trouble speaking or understanding speech
  • Sudden trouble seeing in one or both eyes
  • Dizziness or loss of balance
  • A sudden, severe headache with no known cause

Call 9–1–1 for help as soon as symptoms start. Do not drive yourself to the hospital. It's very important to get checked and treated as soon as possible.

If you're a candidate for clot-busting therapy, you have the best chance for full recovery if treatment to open a blocked artery is given within 4 hours of symptom onset. The sooner treatment occurs, the better your chances of recovery.

Make those close to you aware of stroke symptoms and the need for urgent action. Learning the signs and symptoms of a stroke will allow you to help yourself or someone close to you lower the risk of damage or death due to a stroke.

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