You've probably heard of coronary artery disease, a condition in which the arteries leading to your heart become clogged with fatty deposits called plaques.

The same buildup of plaques can develop in your carotid arteries, a pair of blood vessels that deliver blood to your brain and head. With carotid artery disease, the danger is that clogged-up carotid arteries will block blood flow to your brain and lead to a stroke. Because carotid artery disease develops slowly and often goes unnoticed, a stroke or transient ischemic attack (TIA) — an early warning sign of a future stroke — may be the first outward clue that you have carotid artery disease.

Treatment of carotid artery disease usually involves a combination of lifestyle changes, medications and, in some cases, surgery or a stenting procedure.

In its early stages, carotid artery disease often doesn't produce any signs or symptoms. You and your doctor may not know you have carotid artery disease until it's serious enough to deprive your brain of blood. If that happens, you may develop signs and symptoms such as:

• Sudden weakness, numbness or paralysis in your face, arm or leg, typically on one side of your body
• Slurred or garbled speech or difficulty understanding others
• Sudden blindness in one eye

If you experience any of these signs or symptoms, you may be having a stroke. Seek immediate help.

Even if the signs and symptoms last only a short while — usually less than an hour but, technically, anything less than 24 hours — and then you feel normal, tell your doctor right away. What you may have experienced is a transient ischemic attack (TIA), a temporary shortage of blood to your brain. A TIA is an important sign that you're at high risk of having a full-blown stroke, so don't ignore it. Most people who have a stroke related to carotid artery disease have had a warning in the form of a TIA, prior to the stroke.

Normal, healthy carotid arteries — like any other healthy artery — are smooth and flexible and provide a clear pathway for blood flow. If you place a finger under your jawbone, on either side of your Adam's apple, you're likely to feel your carotid artery pulse. Your carotid arteries carry oxygen- and nutrient-rich blood to your cerebral cortex and other vital brain structures, which are responsible for your day-to-day functioning.

Over time, however, the carotid arteries can become stiff and narrow due to a gradual accumulation of plaques, a process called atherosclerosis. Plaques consist of clumps of cholesterol, calcium, fibrous tissue and other cellular debris that gather at microscopic injury sites within the artery. When a lot of these plaques accumulate, narrowing the carotid artery and substantially restricting blood flow, doctors label this as carotid artery disease.

Factors that stress your arteries and increase the risk of injury, buildup of plaques and disease include the following:

• Aging. With age, your arteries become less elastic and more prone to injury.
• High blood pressure. High blood pressure is an important risk factor for carotid artery disease. Excess pressure on the walls of your arteries can weaken them and leave them more vulnerable to damage.
• Smoking. Nicotine can irritate the inner lining of your arteries. It also increases your heart rate and blood pressure.
• Abnormal blood-fat levels. High levels of low-density lipoprotein (LDL) cholesterol, the "bad" cholesterol, and high levels of triglycerides, a blood fat, encourage the accumulation of plaques.
• Diabetes. Diabetes affects not only your ability to handle glucose appropriately, but also your ability to process fats efficiently, placing you at greater risk of high blood pressure and atherosclerosis.
• Obesity. Carrying excess pounds increases your chances of high blood pressure, atherosclerosis and diabetes.
• Heredity. Having a family history of atherosclerosis or coronary artery disease increases your risk of developing these conditions, as well.
• Physical inactivity. Lack of exercise contributes to a number of conditions, including high blood pressure, diabetes and obesity.

Often, these risk factors occur together, creating even greater risk than if they occur alone. They're also very similar to risk factors for coronary artery disease. In fact, people who have carotid artery disease likely have coronary artery disease, as well.

Talk to your doctor if you have risk factors for carotid artery disease. Your doctor may do some tests to see what shape your arteries are in. Even if you don't have any signs or symptoms, your doctor may recommend aggressive management of your risk factors to protect you from stroke.

If you experience signs or symptoms of a transient ischemic attack or stroke — such as numbness, slurred speech or loss of vision — seek emergency help. Just because they may go away on their own doesn't mean that they can be ignored. Seeing a doctor early increases your chances that carotid artery disease will be detected and treated before a disabling stroke occurs.

In addition to taking a thorough medical history and recording risk factors and any signs or symptoms, your doctor may conduct or request several tests to evaluate the health of your carotid arteries:

• Physical examination. Your doctor may hear a "swooshing" sound (bruit) over the carotid artery in your neck, a sound that's characteristic of a narrowed artery. Or your doctor may observe cholesterol fragments (emboli) in the tiny blood vessels of your retina, at the back of your eye, during an eye examination. A test that compares the arterial blood pressure in each eye with the blood pressure in each arm also may be done.
• Ultrasound. A common, noninvasive test used to check for carotid artery disease is a Doppler ultrasound. This variation of the conventional ultrasound assesses blood flow and pressure - and possible narrowing of the blood vessel — by bouncing high-frequency sound waves (ultrasound) off red blood cells.

• Other imaging options. More detailed imaging tests, such as a computerized tomography angiography (CTA) or magnetic resonance angiography (MRA), may be done if not enough information was obtained from a Doppler ultrasound. By injecting a contrast material into your bloodstream while performing a computerized tomography (CT) scan or magnetic resonance imaging (MRI), your doctor can obtain detailed images of the arteries in your neck and brain.

  A more traditional, and more invasive, imaging procedure called a cerebral angiogram may sometimes be done, but its use is less common, as it carries a slight risk of stroke. This procedure combines X-ray imaging with injection of a dye into your arteries. To begin, a radiologist inserts a thin, flexible tube (catheter) through a small incision, usually in your groin. The catheter is manipulated through your major arteries and into your carotid or vertebral artery. Then, the radiologist injects a dye through the catheter while X-rays are taken. The dye makes the outline of your arteries highly visible on an X-ray.

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Ischemic stroke

The most serious complication of carotid artery disease is stroke. There are different ways carotid artery disease can increase your risk of stroke:

• Reduced blood flow. A carotid artery may become so narrowed by atherosclerosis that not enough blood is able to reach portions of your brain.
• Ruptured plaque. A piece of a plaque may break off and flow to smaller arteries in your brain (cerebral arteries). The fragment may get stuck in one of these smaller arteries, creating a blockage that cuts off blood supply to the area of the brain that the cerebral artery serves (stroke).
• Blood clot blockage. Some plaques are prone to cracking and forming irregular surfaces on the artery wall. When this happens, your body reacts as if to an injury and sends platelets — blood cells that help the clotting process — to the area. A large blood clot may develop in this manner and block or slow the flow of blood through a carotid or cerebral artery, causing a stroke.

A stroke can leave you with permanent brain damage and muscle weakness. In severe cases, it can be fatal.

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Carotid endarterectomy

The goal in treating carotid artery disease is preventing stroke. The method of treatment depends on how narrow your arteries have become. In mild to moderate cases, lifestyle changes and medications may be sufficient to prevent stroke. If blockage is severe or if you've already had a TIA or stroke, surgery or a stenting procedure may be necessary.

Lifestyle changes
Quitting smoking, losing weight, eating healthy foods and exercising regularly are important steps in reducing the stress on your arteries and slowing the progression of atherosclerosis. Lowering the sodium content of your food also may help.

It's also key to manage any chronic conditions you may have, as prescribed by your doctor. If you have high blood pressure, it's important that you stay at or under your blood pressure goal. Similarly, it's important to control your blood sugar levels if you have diabetes, or lower your cholesterol if you have high cholesterol levels.

Medications
Your doctor may ask you to take a daily aspirin or another blood-thinning medicine to avoid the formation of dangerous blood clots. He or she may also recommend medications to control your blood pressure, such as angiotensin-converting enzyme (ACE) inhibitors or calcium channel blockers, or a statin medication to lower your cholesterol.

Procedures
If narrowing in a carotid artery is severe, and especially if you've already experienced a TIA or stroke, it's best to open up the artery and remove the blockage. There are two ways to do this:

• Carotid endarterectomy. This surgical procedure is the most common treatment for severe carotid artery disease. The procedure is done under either local or general anesthesia. After making an incision along the front of your neck, your surgeon opens the affected carotid artery and removes the plaque. The artery is repaired with either stitches or a graft. Most people are discharged from the hospital within 48 hours after the operation. The risks are low, even in adults over 80 years old, as long as they are in good health. Studies have also shown that the surgery has lasting benefit and that it helps prevent strokes.

• Carotid angioplasty and stenting. In some cases, a carotid endarterectomy isn't feasible because the location of the narrowing or blockage is too difficult to access directly. Also, certain conditions — such as severe heart or lung disease, prior neck operations or radiation for neck tumors, or kidney failure — may make surgery too risky. In such cases, your doctor may recommend a balloon procedure called carotid angioplasty and stenting.

  After you've received a local anesthesia, your doctor inserts a long hollow tube (catheter) in your groin artery and threads it through your blood vessel network to the narrowed carotid artery. A tiny balloon at the end of the catheter is inflated to open the narrowed area, and a metal stent — a kind of wire-mesh tubular scaffolding — is inserted to keep the artery from narrowing again. In many instances, the doctor will place a tiny filter, also called an embolic protection device or distal protection device, above the stent to trap any plaque fragments (emboli) that may break loose during the procedure and inadvertently cause a stroke. After the stent is in place, the protective device is removed. You're usually discharged from the hospital the next day. Most people are able to resume normal activities when they get home. Because the procedure is still pretty new, its durability and long-term ability to prevent stroke are still under investigation.

Making healthy choices in your daily life can help prevent or slow the progression of carotid artery disease, and help prevent the occurrence of a TIA or a stroke. Here are some suggestions:

• Don't smoke. Stopping smoking reduces stress on your arteries and cuts your risk of a TIA or a stroke. Several years after quitting, a former smoker's risk of stroke is the same as that of a nonsmoker. It's never too late to quit.
• Limit cholesterol and fat. Cutting back on cholesterol and fat, especially saturated fat, in your diet may reduce buildup of plaques in your arteries.
• Eat a variety of fruits and vegetables. These foods contain such nutrients as potassium, folate and antioxidants, which may protect against a TIA or a stroke.
• Limit sodium. Avoiding salt may not prevent hypertension but excess sodium may increase blood pressure in people who are sensitive to sodium. For healthy adults, most experts recommend a daily sodium intake between 1,500 and 2,400 milligrams a day. If you have high blood pressure, keeping to the lower end of the range may help reduce your blood pressure.
• Exercise regularly. Exercise can lower your blood pressure, increase your level of high-density lipoprotein (HDL) cholesterol — the "good" cholesterol — and improve the overall health of your blood vessels and heart. It also helps you lose weight, control diabetes and reduce stress. If you have high blood pressure, engaging in 30 minutes of moderately vigorous activity (walking or swimming are two examples) on most days of the week is one of the few ways you can lower your pressure without drugs.
• Limit alcohol intake. Drink alcohol in moderation, if at all. The recommended limit is no more than one drink daily for women and two a day for men.
• Maintain a healthy weight. Being overweight contributes to other risk factors, such as high blood pressure, cardiovascular disease and diabetes. Losing weight with diet and exercise may lower your blood pressure and improve your cholesterol levels.
• Control chronic conditions. You can manage both diabetes and high blood pressure with diet, exercise, weight control and, when necessary, medication.