Overview of arteries and arterial diseases

Arteries are blood vessels that carry oxygenated blood away from your heart and lungs to deliver the oxygen and nutrients to all the cells in your body.

Other blood vessels that make up the circulatory system include veins and capillaries. Veins bring the deoxygenated blood and carbon dioxide back to the heart and lungs. Capillaries are the smallest of your body's blood vessels and are the connection of arteries to veins.

Arteries are the thickest blood vessels, with a smooth lining and flexible walls that allow blood to pass freely through your body. Veins are not as elastic as arteries, but they contain valves that prevent blood from flowing backward. Both veins and arteries carry blood throughout your body. Blood with oxygen comes from the lungs to the heart and then travels away from the heart through arteries. It travels and exchanges oxygen for carbon dioxide and other waste throughout the body in capillaries. Blood with carbon dioxide goes back to the heart through veins and then travels to the lungs. In the lungs, oxygen is put into the blood and carbon dioxide is taken out of the blood as you breathe.

Blood is continuously pumped through your body by the heart. There are two major arteries leaving the heart: the pulmonary artery and the aorta. The heart pumps blood into the pulmonary artery where it is carried to the lungs to pick up oxygen. The oxygen-rich blood returns to the heart where it's then pumped out the aorta.

The aorta is the largest artery in the body. It's divided into three sections:

• Ascending aorta. The heart itself gets oxygen from arteries that come off the ascending aorta.
• Aortic arch. The head, neck and arms get oxygen from arteries that come off the aortic arch.
• Descending aorta, which is further subdivided into the thoracic aorta and abdominal aorta. The small branches of the thoracic aorta supply blood to the ribs and certain structures in the chest. The stomach, intestines, kidneys and other vital organs get oxygen from arteries that come off the abdominal aorta.

The aorta carries oxygen-rich blood away from the heart to smaller vessels that reach the rest of your body. Different arteries bring blood to various locations in the body, including the following:

• The coronary arteries bring blood to the heart.
• The carotid arteries bring blood to the head, face, brain and neck.
• The vertebral arteries bring blood to the brain and spine.
• The iliac arteries bring blood to the pelvis.
• The femoral artery brings blood to the legs.
• The subclavian arteries bring blood to the neck, head and arms.
• The celiac and mesenteric arteries bring blood to the digestive system and abdomen.

Healthy arteries are strong and elastic, but over time they can narrow and become less flexible. A substance called plaque can build up on the inner walls of your arteries. Plaque is made up of fat, cholesterol, calcium and other substances found in the blood. Plaque hardens and narrows your arteries. Hardening of the arteries is also known as atherosclerosis.

Most diseases of the arteries are related to atherosclerosis, which can affect arteries all over the body. Depending on which artery is affected, atherosclerosis can cause several health problems. Some of these include:

• Carotid artery disease is a buildup of plaque in the carotid arteries, which bring blood to the brain.
• Coronary artery disease, also called coronary heart disease, is a collection of plaque in the coronary arteries, which carry blood to the heart muscle.
• Renal artery stenosis is plaque that builds up on the walls of the renal arteries, which transport blood to the kidneys.
• Peripheral artery disease is a buildup of plaque in the arteries that bring blood to the extremities, especially the legs.
• Vertebrobasilar insufficiency is poor blood flow to the posterior (back) portion of the brain because of plaque buildup in the vertebrobasilar arteries. These blood vessels supply nutrients and oxygen to the parts of the brain that control breathing, heart rate, vision, coordination, balance and many other essential functions.
• Aortic aneurysm and aortic dissection can occur from a narrowing of the aorta due to hardened plaque. An aneurysm is an abnormal bulging of the wall of the aorta. A dissection is a tear in the aorta.

Carotid artery disease, also called carotid artery stenosis, occurs when plaque builds up and clogs the carotid arteries, which deliver oxygen-rich blood to your brain and head. Risk factors for carotid artery disease are the same as for atherosclerosis anywhere else in your body and include older age, smoking, high blood pressure, diabetes, high cholesterol, obesity and a family history of heart disease.

Carotid artery disease is a common cause of stroke. A stroke happens when blood stops flowing to any part of your brain, damaging brain cells. The effects of a stroke depend on the part of the brain that was damaged and the amount of damage done. The middle cerebral artery is the artery most often blocked in a stroke. If a posterior cerebral artery becomes blocked or bleeds in a stroke, a large part of the back of the brain loses its supply of blood and oxygen.

Coronary artery disease, or coronary heart disease, is similar to carotid artery disease. It usually develops as a result of atherosclerosis and narrows your coronary arteries, decreasing blood flow to your heart. At first, the decreased blood flow may not cause any coronary artery disease symptoms. As plaque continues to build up in your coronary arteries, however, you may develop coronary artery disease signs and symptoms, including:

• Shortness of breath. If your heart can't pump enough blood to meet your body's needs, you may develop shortness of breath or extreme fatigue with even simple exertion, like walking.
• Angina (chest pain). It occurs when your heart muscle doesn't get enough oxygen-rich blood. Angina may feel like pressure or squeezing in your chest. You also may feel it in your shoulders, arms, neck, jaw or back. Angina pain may even feel like indigestion. The pain tends to get worse with activity and go away with rest.
• Heart attack. A completely blocked coronary artery will cause a heart attack, which means that enough oxygen isn't getting to your heart muscle. If blood flow isn't restored quickly, the section of heart muscle begins to die. Most heart attacks involve discomfort in the center or left side of the chest that often lasts for more than a few minutes or goes away and comes back. The discomfort can feel like uncomfortable pressure, squeezing, fullness or pain. Sometimes a heart attack occurs without any apparent signs or symptoms.

Your healthcare provider will ask questions about your medical history, do a physical exam and order routine blood tests. If you're at high risk for heart disease or already have symptoms, your doctor can use several tests to make a diagnosis. Coronary heart disease or coronary artery disease tests may include:

• Electrocardiogram (ECG or EKG). This measures the electrical activity, rate and regularity of your heartbeat.
• Echocardiogram. An echocardiogram uses ultrasound to create a picture of the heart.
• Exercise stress test. This measures your heart rate while you walk on a treadmill to determine how well your heart is working when it has to pump more blood.
• Chest X-ray. This imaging test uses X-rays to create a picture of the heart, lungs and other organs in the chest.
• Cardiac catheterization. This test checks the inside of your arteries for blockage by inserting a thin, flexible tube through an artery in the groin, arm or neck to reach the heart. This allows a healthcare professional to measure blood pressure within the heart and the strength of blood flow through the heart's chambers. They may also collect blood samples from the heart or inject dye into the coronary arteries.
• Coronary angiogram. This test uses X-ray imaging to detect dye injected into the coronary arteries to find out to if the vessels are blocked or narrowed.

Treatment for coronary heart disease usually involves heart-healthy lifestyle changes and medications, if needed. Lifestyle changes include maintaining a healthy weight, eating a diet low in saturated and trans fats, getting regular exercise and not smoking. Your doctor may prescribe cholesterol-lowering medications, medicines to lower your blood pressure, and aspirin or other medicines that help prevent blood clots. Certain medical procedures can restore and improve blood flow. These include:

• Angioplasty and coronary stenting. During an angioplasty, your doctor inserts a tiny balloon at the site of the blockage and expands it to widen the narrowed artery. Your doctor then may implant a small metal coil, called a stent, in the clogged artery to keep the artery open and reduce the risk of it narrowing again.
• Coronary artery bypass grafting (CABG). Your doctor may recommend this type of surgery if your arteries are narrowed or blocked in multiple areas, or your left main coronary artery (also known as the left anterior descending artery) is narrowed.

Renal artery stenosis is the narrowing of one or both renal arteries (the blood vessels that carry blood to the kidneys from the aorta). Narrowing of the arteries caused by a buildup of plaque prevents normal amounts of oxygen-rich blood from reaching your kidneys. The reduction of blood flow can cause high blood pressure or lead to kidney disease.

Peripheral artery disease is a chronic disease in which narrowed arteries caused by plaque buildup reduce blood flow to your limbs. It mainly occurs in arteries that supply blood to the legs, such as the ileac artery, femoral artery and popliteal artery. The reduction of blood flow can lead to claudication, which is pain in the legs and buttocks when walking, and can also lead to severe and dangerous blockages of blood flow.

Vertebrobasilar insufficiency occurs when blood flow to the vertebrobasilar arteries is restricted, most often due to a buildup of plaque. These are the main blood vessels that provide blood flow to the back of the brain. A person with vertebrobasilar disease is at increased risk for a stroke.

An aortic aneurysm occurs when the walls of the aorta bulge or dilate. An aneurysm that occurs in the chest portion of the aorta is called a thoracic aortic aneurysm. An aneurysm that occurs in the abdominal portion of the aorta is called an abdominal aortic aneurysm. If the weakened walls of your aorta burst or rupture, the aneurysm can cause sudden life-threatening bleeding inside your body. Having an aneurysm increases the risk of an aortic dissection.

An aortic dissection, or a tear in wall of the aorta, occurs in places where the aortic wall is weak. Blood leaks through the tear and causes the inner and middle layers of the aorta to separate or dissect. The dissection can sometimes cause a rupture in the outer wall, which can be fatal.

The same lifestyle habits that can help treat problems caused by atherosclerosis can also help prevent it from developing in the first place. Leading a healthy lifestyle can help keep your arteries flexible and free of plaque buildup. To help protect the health of your blood vessels:

• Don't smoke
• Eat a healthy diet that's rich in fruits and vegetables and limit salt, sugar, alcohol, and saturated fat and trans fats
• Maintain a healthy weight
  
• Keep your blood pressure, cholesterol and blood sugar in check
• Exercise regularly

Clinically reviewed and updated July 2023.