Learn About Carotid Artery Health and Blockage Signs

Understanding the Carotid Arteries and Their Function

The carotid arteries are two major blood vessels in your neck that carry oxygen-rich blood from your heart to your brain. You have one carotid artery on each side of your neck, and together they supply roughly 80% of the blood that reaches your brain. These arteries are critical to your survival—without proper blood flow through them, your brain cannot function properly. The carotid arteries branch from the aorta, which is the main artery leaving your heart. As blood travels up through these vessels, it continues to divide into smaller branches that deliver oxygen and nutrients throughout the brain.

Each carotid artery has two sections: the common carotid artery, which is the main vessel, and the internal carotid artery, which branches off and enters the brain. A third artery, the external carotid artery, supplies blood to the face and scalp. Because the carotid arteries handle such a large volume of blood flow to the brain, any problem with these vessels can have serious consequences. Even partial blockage can reduce the amount of oxygen reaching brain tissue. Complete blockage can cut off blood flow entirely, which is why carotid artery disease is considered a major health risk.

You can actually feel your carotid arteries by gently pressing on either side of your neck below your jaw. You should feel a pulse there. This is an easy way to check that blood is flowing through these vessels. The location of the carotid arteries near the surface of the neck also makes them easier for doctors to examine using ultrasound and other imaging tests. Understanding where these arteries are and what they do is the first step in recognizing why their health matters.

Practical Takeaway: Your carotid arteries deliver most of the blood your brain needs to function. Keeping these vessels healthy is essential for preventing stroke and protecting your brain health. Regular check-ups and knowing the warning signs of problems can help you catch issues before they become serious.

How Blockage Develops in Carotid Arteries

Carotid artery blockage typically develops gradually over many years through a process called atherosclerosis. In atherosclerosis, fatty deposits, cholesterol, and other substances accumulate on the inner walls of arteries, forming a buildup called plaque. This process is often silent—you may have no symptoms while plaque is building up inside your vessels. The buildup starts when the inner lining of the artery (called the endothelium) becomes damaged. This damage can result from high blood pressure, high cholesterol, smoking, or inflammation in the body.

Once plaque begins to form, it continues to grow as more lipids and cellular material deposit in the artery. Over time, the plaque hardens and narrows the artery, similar to how mineral buildup can narrow a water pipe. As the artery narrows, less blood can flow through it. When a carotid artery becomes 50% or more blocked, doctors consider it significant. A blockage of 70% or more is considered severe and poses a substantial stroke risk. According to research, carotid artery disease affects approximately 1 in 20 adults over age 65, though many people don't know they have it.

The dangerous part is that plaque isn't always stable. Sometimes the outer layer of a plaque deposit can rupture or crack. When this happens, the body responds by forming a blood clot at the site of the rupture. A small piece of this clot or plaque can break free and travel through the bloodstream to the brain, where it may lodge in a smaller artery and block blood flow. This event can trigger a stroke. Alternatively, severe narrowing can reduce blood flow so much that the brain doesn't receive enough oxygen, which can also cause a stroke or transient ischemic attack (TIA), sometimes called a "mini-stroke."

Practical Takeaway: Blockage in carotid arteries develops slowly over years, often without symptoms. Understanding that plaque can rupture and cause blood clots helps explain why early detection and management of risk factors are important steps in protecting your brain health.

Recognizing the Signs and Symptoms of Carotid Artery Disease

Many people with carotid artery blockage experience no symptoms at all. The condition is often discovered by accident during a physical examination when a doctor hears an unusual sound called a "bruit" while listening to the carotid artery with a stethoscope. However, when symptoms do occur, they are often related to the brain not receiving enough blood flow. The symptoms can vary depending on which artery is blocked and how severely, and whether a clot or plaque fragment has traveled to the brain.

A transient ischemic attack (TIA) is often the first warning sign of carotid artery disease. A TIA causes stroke-like symptoms that last only minutes to hours and then resolve completely. Common TIA symptoms include sudden weakness or numbness on one side of the body, sudden difficulty speaking or slurred speech, sudden vision loss in one eye, sudden dizziness, and sudden severe headache. Some people describe TIA symptoms as a temporary loss of function that feels like something is wrong, but then improves on its own. TIAs are serious warning signs—they indicate that blood flow to the brain is being interrupted and that a full stroke may happen next.

A completed stroke occurs when blood flow to the brain is blocked long enough to cause permanent brain damage. Stroke symptoms are similar to TIA symptoms but are more severe and do not resolve on their own. Signs of stroke include sudden weakness or numbness on one side of the face, arm, or leg; sudden confusion or difficulty understanding speech; sudden difficulty speaking; sudden vision problems; sudden loss of balance or coordination; and sudden severe headache without a known cause. The acronym FAST helps people remember stroke warning signs: Face drooping, Arm weakness, Speech difficulty, and Time to call emergency services. Any of these symptoms warrant an immediate call to emergency services.

Practical Takeaway: Most people with carotid artery blockage have no symptoms, but TIA symptoms (temporary weakness, speech problems, or vision loss) are serious warning signs that a stroke may be coming. Knowing these signs and acting quickly can be lifesaving, as treatments given within hours of symptoms can reduce stroke damage.

Risk Factors That Contribute to Carotid Artery Disease

Several conditions and lifestyle factors increase the likelihood that you will develop carotid artery disease. Age is one factor—the risk increases significantly after age 50 for men and after age 60 for women. Men are also more likely to develop carotid artery disease than women. Family history matters too; if close relatives had heart disease or stroke at an early age, your risk may be higher. These are risk factors you cannot change, but they help explain why some people are more vulnerable than others.

High blood pressure, or hypertension, is one of the most common modifiable risk factors for carotid artery disease. High blood pressure damages the lining of arteries and makes them more susceptible to plaque buildup. According to the American Heart Association, nearly half of American adults have high blood pressure, yet many don't know it. High cholesterol is another major risk factor. LDL cholesterol, often called "bad cholesterol," contributes to plaque formation. When LDL levels are elevated, particles accumulate in artery walls more readily. Smoking is also a significant risk factor—it damages blood vessel linings and promotes inflammation, accelerating atherosclerosis. People who smoke have roughly double the risk of carotid artery disease compared to nonsmokers.

Diabetes increases stroke risk substantially. People with diabetes have higher levels of blood sugar, which can damage blood vessel walls over time. Being overweight or obese, physical inactivity, and a diet high in saturated fats and sodium all contribute to the development of carotid artery disease. Chronic inflammation from conditions like rheumatoid arthritis or certain infections may also play a role. Additionally, certain conditions like atrial fibrillation (an irregular heartbeat) increase the risk of blood clots, which can travel to the carotid arteries or beyond. Understanding your personal risk factors allows you to take action on those you can control.

Practical Takeaway: While you cannot change age or family history, you can reduce your risk by managing blood pressure, cholesterol, and weight; quitting smoking; exercising regularly; and eating a heart-healthy diet. Taking action on the risk factors you control is one of