The carotid arteries provide the main blood supply to the brain. There carotid arteries are located on each side of your neck under the jawline.

Carotid artery disease is a condition in which these arteries become narrowed or blocked. When the arteries become narrowed, the condition is called carotid stenosis.

Carotid stenosis; Stenosis - carotid

Carotid artery disease occurs when sticky, fatty substances called plaque build up in the inner lining of the arteries. See: Atherosclerosis (hardening of the arteries)

The plaque may slowly block or narrow the carotid artery or cause a clot (thrombus) to form. Clots can lead to stroke.

Risk factors for blockage or narrowing of the arteries include:

• High blood pressure
• Diabetes
• Heart disease
• High cholesterol
• Heavy alcohol use
• Kidney disease, especially when dialysis is needed
• Cocaine abuse
• Family history of stroke
• Increasing age

Smoking is also a risk factor. Smoking increases the risk of most types of stroke. People who smoke one pack a day have over two times the risk of stroke compared to nonsmokers.

Two uncommon conditions called Marfan syndrome and fibromuscular dysplasia (abnormal growth or development of the cells in the walls of carotid arteries) may also cause narrowing of the carotid arteries.

You may not have any symptoms.

You may have symptoms of a stroke or a transient ischemic attack (TIA). Some of these symptoms include:

• Weakness in one part of your body
• Blurred vision
• Confusion
• Loss of memory
• Problems with speech and language
• Loss of sensation

Your health care provider will perform a physical exam. The health care provider may hear an abnormal sound called a bruit when using a stethoscope to listen to the blood flow in your neck.

A physical exam may also reveal clots in the blood vessels of the eye. If you have had a stroke or TIA, a neurological exam will reveal other problems.

The following tests may be done:

• Blood tests to check cholesterol and triglycerides
• Blood sugar (glucose) test
• Ultrasound of the carotid arteries (carotid duplex or doppler study) to see how well blood is flowing through the carotid artery

The following imaging tests may be used to examine the blood vessels in the neck and brain:

• Magnetic resonance angiography (MRA)
• Computerized tomographic angiography (CTA)
• Carotid or cerebral angiography

Treatment options include:

• No treatment, other than checking your carotid artery with tests every year
• Medicine and diet to lower your cholesterol and control your blood pressure
• Blood-thinning medicines to lower your risk of stroke; some of these medicines are aspirin, clopidogrel (Plavix), and warfarin (Coumadin)

Surgery, called carotid endarterectomy, to remove the buildup in your carotid arteries may help prevent new strokes from occurring in persons with large blockages in their neck arteries. See: Carotid artery surgery

Stroke is a leading cause of death in the United States. Some people who have a stroke recover most or all of their functions. Others die from the stroke itself or from complications. About half of those who have a stroke have long-term problems.

The major complication associated with carotid artery disease are:

• Transient ischemic attack (TIA). This is an episode in which a person has stroke -like symptoms for less than 24 hours, usually less than 1-2 hours. A TIA is often considered a warning sign that a stroke may happen in the future if something is not done to prevent it.
• Stroke. A stroke can happen when a blood vessel in any part of the brain is blocked. The blood through the narrowed carotid artery may slow so much that a clot forms. A stroke may also occur if a small piece of a blood clot breaks off and travels to a smaller artery in the brain.

Go to the emergency room or call the local emergency number (such as 911) as soon as symptoms occur. When having a stroke, every second of delay can result in more brain injury.

The following can help prevent a stroke:

• Avoid fatty foods. Follow a healthy, low-fat diet.
• Do not drink more than 1 to 2 alcoholic drinks a day.
• Exercise regularly: 30 minutes a day if you are not overweight; 60 - 90 minutes a day if you are overweight.
• Quit smoking.
• Get your blood pressure checked every 1 - 2 years, especially if high blood pressure runs in your family. If you have high blood pressure, heart disease, or have had stroke, you need to have it checked more often. Ask your doctor.
• Everyone should keep their blood pressure below 120-130/80 mmHg. If you have diabetes or have had a stroke, you may need to strive for a lower blood pressure. Ask your doctor what it should be.
• Adults should have their cholesterol checked every 5 years and treated, if needed. If you have been treated for high cholesterol, you will need it checked more often.
• If you have diabetes, heart disease, or hardening of the arteries somewhere else in your body, your LDL "bad" cholesterol should be lower than 70 mg/dL.
• Follow your doctor's treatment recommendations if you have high blood pressure, diabetes, high cholesterol, and heart disease.

Goldstein LB. Prevention and management of stroke. In: Libby P, Bonow RO, Mann DL, Zipes DP, eds. Libby: Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed. Saunders;2007:chap 58.

Zivin JA. Hemorrhagic cerebrovascular disease. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 432.