What is carotid artery disease?

The carotid arteries are the main blood vessels that carry blood and oxygen to the brain. When these arteries become narrowed, it’s called carotid artery disease. It may also be called carotid artery stenosis. The narrowing is caused by atherosclerosis. This is the buildup of fatty substances, calcium, and other waste products inside the artery lining. Carotid artery disease is similar to coronary artery disease, in which buildup occurs in the arteries of the heart and can cause a heart attack.

Carotid artery disease reduces the flow of oxygen to the brain. The brain needs a constant supply of oxygen to work. Even a brief pause in blood supply can cause problems. Brain cells start to die after just a few minutes without blood or oxygen. If the narrowing of the carotid arteries becomes severe enough that blood flow is blocked, it can cause a stroke. If a piece of plaque breaks off it can also block blood flow to the brain. This too can cause a stroke.

What causes carotid artery disease?

Atherosclerosis causes most carotid artery disease. In this condition, fatty deposits build up along the inner layer of the arteries forming plaque. The thickening narrows the arteries and decreases blood flow or completely blocks the flow of blood to the brain.

Who is at risk for carotid artery disease?

Risk factors associated with atherosclerosis include:

  • Older age
  • Male
  • Family history
  • Race
  • Genetic factors
  • High cholesterol
  • High blood pressure
  • Smoking
  • Diabetes
  • Overweight
  • Diet high in saturated fat
  • Lack of exercise

Although these factors increase a person's risk, they don't always cause the disease. Knowing your risk factors can help you make lifestyle changes and work with your healthcare provider to reduce chances you will get the disease.

What are the symptoms of carotid artery disease?

Carotid artery disease may have no symptoms. Sometimes, the first sign of the disease is a transient ischemic attack (TIA) or stroke.

A transient ischemic attack (TIA) is a sudden, temporary loss of blood flow to an area of the brain. It usually lasts a few minutes to an hour. Symptoms go away entirely within 24 hours, with complete recovery. When symptoms continue, it is a stroke. Symptoms of a TIA or stroke may include:

  • Sudden weakness or clumsiness of an arm or leg on one side of the body
  • Sudden paralysis of an arm or leg on one side of the body
  • Loss of coordination or movement
  • Confusion, decreased ability to concentrate, dizziness, fainting, or headache
  • Numbness or loss of feeling in the face or in an arm or leg
  • Temporary loss of vision or blurred vision
  • Inability to speak clearly or slurred speech

If you or a loved one has any of these symptoms, call for medical help right away. A TIA may be a warning sign that a stroke is about to occur. But TIAs don't precede all strokes.

The symptoms of a TIA and stroke are the same. A stroke is loss of blood flow (ischemia) to the brain that continues long enough to cause permanent brain damage. Brain cells start to die after just a few minutes without oxygen.

The disability that occurs from stroke depends on the size and location of the area of the brain that suffered loss of blood flow. This may include problems with:

  • Moving
  • Speaking
  • Thinking
  • Remembering
  • Bowel and bladder function
  • Eating
  • Emotional control
  • Other vital body functions

Recovery also depends on the size and location of the stroke. A stroke may result in long-term problems, such as weakness in an arm or leg. It may cause paralysis, loss of speech, or even death.

The symptoms of carotid artery disease may look like other health conditions or problems. Always see your healthcare provider for a diagnosis.

How is carotid artery disease diagnosed?

Your healthcare provider will ask about your health history and do a physical exam. You will also need tests for carotid artery disease. These may include:

  • Listening to the carotid arteries. For this test, your healthcare provider places a stethoscope over the carotid artery to listen for a sound called a bruit (BREW-ee). This sound is made when blood passes through a narrowed artery. A bruit can be a sign of atherosclerosis. But an artery may be diseased without making this sound.
  • Carotid artery duplex scan. This test is done to assess the blood flow of the carotid arteries. A probe called a transducer sends out ultrasonic sound waves. The transducer is like a microphone. When the transducer is placed on the carotid arteries at certain locations and angles, the sound waves move through the skin and other body tissues to the blood vessels, where the waves echo off of the blood cells. The transducer sends the waves to an amplifier, so the provider can hear the sound waves. Absence of or faintness of these sounds may mean blood flow is blocked.
  • MRI. This procedure uses a combination of large magnets, radio waves, and a computer to make detailed images of organs and structures in the body. For this test, you lie inside a big tube while magnets pass around your body. It’s very loud. 
  • MR angiography (MRA). This procedure uses MRI technology and IV contrast dye to make the blood vessels visible. Contrast dye causes blood vessels to appear solid on the MRI image so the doctor can see them.
  • CT angiography (CTA). This test uses X-rays and computer technology along with contrast dye to make detailed images  of the body. A CTA shows pictures of blood vessels and tissues and is helpful in finding narrowed blood vessels.  
  • Angiography. This test is used to assess the how blocked the carotid arteries are by taking X-ray images while a contrast dye is injected. The contrast dye helps the healthcare provider see the shape and flow of blood through the arteries as X-ray images are made.

How is carotid artery disease treated?

Treatment will depend on your symptoms, age, and general health. It will also depend on how severe the condition is.

If a carotid artery is less than half narrowed, it is often treated with medicine and lifestyle changes. If the artery is between 50% and 70% narrowed, medicine or surgery may be used, depending on your case.

Medical treatment for carotid artery disease may include the following.

Lifestyle changes

  • Quitting smoking. Quitting smoking can reduce the risk for carotid artery disease and cardiovascular disease. All nicotine products, including electronic cigarettes, constrict the blood vessels. This decreases blood flow through the arteries.
  • Lowering cholesterol. Eat a low-fat, low-cholesterol diet. Eat plenty of vegetables, lean meats (no red meats), fruits, and high-fiber grains. Don't eat processed foods, or foods high in saturated and trans-fats. When diet and exercise are not enough to control cholesterol, you may need medicines.
  • Lowering blood sugar. High blood sugar (glucose) can cause damage and inflammation to the lining of the carotid arteries. Control glucose levels through a low-sugar diet, and regular exercise. If you have diabetes, you may need medicine or other treatment.
  • Exercising. Lack of exercise can cause weight gain and raise blood pressure and cholesterol. Exercise can help maintain a healthy weight and reduce risks for carotid artery disease.
  • Lowering blood pressure. High blood pressure causes wear and tear and inflammation in blood vessels increasing the risk for artery narrowing. Blood pressure should be below 140/90 mm/Hg for most people. People with diabetes may need even lower blood pressure.


Medicines that may be used to treat carotid artery disease include:

  • Antiplatelets. These medicines make platelets in the blood less able to stick together and cause clots. Aspirin, clopidogrel, and dipyridamole are examples of antiplatelets.
  • Cholesterol-lowering medicines. Statins are a group of cholesterol-lowering medicines. They include simvastatin and atorvastatin. Studies have shown that certain statins can decrease the thickness of the carotid artery wall and increase the size of the opening of the artery.
  • Blood pressure-lowering medicines. Several different medicines work to lower blood pressure.

If a carotid artery is narrowed from 50% to 70%, you may need more aggressive treatment, especially if you have symptoms.

Surgery is usually advised for carotid narrowing of more than 70%. Surgical treatment decreases the risk for stroke after symptoms such as TIA or minor stroke.

Surgical treatment of carotid artery disease includes:

  • Carotid endarterectomy (CEA). This is surgery to remove plaque and blood clots from the carotid arteries. Endarterectomy may help prevent a stroke in people who have symptoms and a narrowing of 70% or more.
  • Carotid artery angioplasty with stenting (CAS). This is an option for people who are unable to have carotid endarterectomy. It uses a very small hollow tube, or catheter, that is thread through a blood vessel in the groin to the carotid arteries. Once the catheter is in place, a balloon is inflated to open the artery and a stent is placed. A stent is a thin, metal-mesh framework used to hold the artery open.

What are possible complications of carotid artery disease?

The main complication of carotid artery disease is stroke. Stroke can cause serious disability and may be fatal.

Can carotid artery disease be prevented?

You can prevent or delay carotid artery disease in the same way that you would prevent heart disease. This includes:

  • Diet changes. Eat a healthy diet that includes plenty of fresh fruits and vegetables, lean meats such as poultry and fish, and low-fat or non-fat dairy products, Limit your intake of salt, sugar, processed foods, saturated fats, and alcohol. 
  • Exercise. Aim for 40 minutes of moderate to vigorous-level physical activity at least 3 to 4 days per week.
  • Manage weight. If you are overweight, take steps to lose weight. 
  • Quit smoking. If you smoke, break the habit. Enroll in a stop-smoking program to improve your chances of success. Ask your doctor about prescription options.
  • Control stress. Learn to manage stress in your home and work life.

When should I call my healthcare provider?

Learn the symptoms of stroke and have your family members also learn them. If you think you are having symptoms of a stroke, call 911 right away.

Key points about carotid artery disease

  • Carotid artery disease is narrowing of the carotid arteries. These arteries deliver oxygenated blood from the heart to the brain.
  • Narrowing of the carotid arteries can cause a stroke or symptoms of a stroke and should be treated right away.
  • Eating a low-fat, low-cholesterol diet that is high in vegetables, lean meats, fruits, and high fiber is one way to reduce the risk of carotid disease. Exercise, quitting smoking, blood pressure control, and medicine can also help.
  • Opening the carotid arteries once they are narrowed can be done with a surgery or with angioplasty and a stent.
  • Carotid artery disease may not have symptoms, but if you have significant risk factors, see your healthcare provider for screening and diagnosis.