Atherosclerosis is a disease in which plaque (plak) builds up inside your arteries. Arteries are blood vessels that carry oxygen-rich blood to your heart and other parts of your body.
Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. Over time, plaque hardens and narrows your arteries, limiting the flow of oxygen-rich blood to your organs and other parts of your body. This can lead to serious problems, including heart attack, stroke, or even death.
Causes | Risk Factors | Signs and Symptoms | Diagnosis | Prevention
The exact cause of atherosclerosis isn’t known. However, studies show that atherosclerosis is a slow, complex disease that may start in childhood. It develops faster as you age.
Atherosclerosis may start when certain factors damage the inner layers of the arteries. These factors include:
- High amounts of certain fats and cholesterol in the blood
- High blood pressure
- High amounts of sugar in the blood due to insulin resistance or diabetes
When damage occurs, your body starts a healing process. The healing may cause plaque to build up where the arteries are damaged. Eventually, a section of plaque can break open, causing a blood clot to form at the site. A blood clot will narrow the artery even more and may worsen angina (chest pain) or cause a heart attack or stroke.
Researchers continue to look for the causes of atherosclerosis. They hope to find answers to questions such as:
- Why and how do the arteries become damaged?
- How does plaque develop and change over time?
- Why does plaque crack and lead to blood clots?
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Coronary heart disease (atherosclerosis of the coronary arteries) is the leading cause of death for both men and women in the United States. The exact cause of atherosclerosis isn’t known. However, certain traits, conditions, or habits may raise your risk for the disease. These conditions are known as risk factors. Your chances of developing atherosclerosis increase with the number of risk factors you have.
You can control most risk factors and help prevent or delay atherosclerosis. Other risk factors can’t be controlled.
Major Risk Factors
- Unhealthy blood cholesterol levels. This includes high LDL cholesterol (sometimes called “bad” cholesterol) and low HDL cholesterol (sometimes called “good” cholesterol).
- High blood pressure. Blood pressure is considered high if it stays at or above 140/90 mmHg over time. If you have diabetes or chronic kidney disease, high blood pressure is defined as 130/80 mmHg or higher. (The mmHg is millimeters of mercury — the units used to measure blood pressure.)
- Smoking. Smoking can damage and tighten blood vessels, raise cholesterol levels, and raise blood pressure. Smoking also doesn’t allow enough oxygen to reach the body’s tissues.
- Insulin resistance. This condition occurs if the body can’t use its insulin properly. Insulin is a hormone that helps move blood sugar into cells where it’s used.
- Diabetes. This is a disease in which the body’s blood sugar level is too high because the body doesn’t make enough insulin or doesn’t use its insulin properly.
- Overweight or obesity. The terms “overweight” and “obesity” refer to a person’s overall body weight and whether it’s too high. Overweight is having extra body weight from muscle, bone, fat, and/or water. Obesity is having a high amount of extra body fat.
- Lack of physical activity. A lack of physical activity can worsen other risk factors for atherosclerosis, such as unhealthy blood cholesterol levels, high blood pressure, diabetes, and overweight and obesity.
- Unhealthy diet. An unhealthy diet can raise your risk of atherosclerosis. Foods that are high in saturated and trans fats, cholesterol, sodium (salt), and sugar can worsen other atherosclerosis risk factors.
- Age. As you get older, your risk of atherosclerosis increases. Genetic or lifestyle factors cause plaque to build in your arteries as you age. By the time you’re middle-aged or older, enough plaque has built up to cause signs or symptoms. In men, the risk increases after age 45. In women, the risk increases after age 55.
- Family history of early heart disease. Your risk of atherosclerosis increases if your father or a brother was diagnosed with heart disease before 55 years of age, or if your mother or a sister was diagnosed with heart disease before 65 years of age.
Emerging Risk Factors
- Scientists continue to study other possible risk factors for atherosclerosis.
- High levels of a protein called C-reactive protein (CRP) in the blood may raise the risk of atherosclerosis and heart attack. High levels of CRP are proof of inflammation in the body. Inflammation is the body’s response to injury or infection. Damage to the arteries’ inner walls seems to trigger inflammation and help plaque grow.
- People who have low CRP levels may develop atherosclerosis at a slower rate than people who have high CRP levels. Research is under way to find out whether reducing inflammation and lowering CRP levels also can reduce the risk of atherosclerosis.
- High levels of fats called triglycerides in the blood also may raise the risk of atherosclerosis, particularly in women.
- Studies are under way to determine whether genetics may play a role in atherosclerosis risk.
Other Factors That Affect AtherosclerosisOther risk factors also may raise your risk for atherosclerosis. These include:
- Sleep apnea. Sleep apnea is a disorder in which you have one or more pauses in breathing or shallow breaths while you sleep. Untreated sleep apnea can raise your chances of having high blood pressure, diabetes, and even a heart attack or stroke.
- Stress. Research shows that the most commonly reported “trigger” for a heart attack is an emotionally upsetting event, particularly one involving anger.
- Alcohol. Heavy drinking can damage the heart muscle and worsen other risk factors for atherosclerosis. Men should have no more than two drinks containing alcohol a day. Women should have no more than one drink containing alcohol a day.
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Signs and Symptoms
Atherosclerosis usually doesn’t cause signs and symptoms until it severely narrows or totally blocks an artery. Many people don’t know they have the disease until they have a medical emergency, such as a heart attack or stroke.
Some people may have signs and symptoms of the disease. Signs and symptoms will depend on which arteries are affected.
Coronary ArteriesThe coronary arteries supply oxygen-rich blood to your heart. When plaque narrows or blocks these arteries (a condition called coronary heart disease, or CHD), a common symptom is angina. Angina is chest pain or discomfort that occurs when your heart muscle doesn’t get enough oxygen-rich blood.
Angina may feel like pressure or a squeezing pain in your chest. You also may feel it in your shoulders, arms, neck, jaw, or back. This pain tends to get worse with activity and go away when you rest. Emotional stress also can trigger the pain.
Other symptoms of CHD are shortness of breath and arrhythmias (ah-RITH-me-ahs). Arrhythmias are problems with the rate or rhythm of the heartbeat.
Plaque also can form in the heart’s smallest arteries. When this happens, it’s called coronary microvascular disease (MVD). In addition to angina and shortness of breath, coronary MVD also may cause sleep problems, fatigue (tiredness), and lack of energy.
Carotid ArteriesThe carotid arteries supply oxygen-rich blood to your brain. When plaque narrows or blocks these arteries (a condition called carotid artery disease), you may have symptoms of a stroke. These symptoms may include:
- Sudden weakness or numbness in the face or limbs, often on just one side of the body
- The inability to move one or more of your limbs
- Trouble speaking and understanding
- Sudden trouble seeing in one or both eyes
- Dizziness or loss of balance
- A sudden, severe headache with no known cause
Peripheral ArteriesPlaque also can build up in the major arteries that supply oxygen-rich blood to the legs, arms, and pelvis. When this happens, it’s called peripheral arterial disease. If these major arteries are narrowed or blocked, it can lead to numbness, pain, and, sometimes, dangerous infections.
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Your doctor will diagnose atherosclerosis based on your medical and family histories, a physical exam, and results from tests.
If you have atherosclerosis, a primary care doctor, such as an internist or family practitioner, may handle your care. Your doctor may recommend other health care specialists if you need expert care. These specialists may include:
- A cardiologist. This is a doctor who specializes in diagnosing and treating heart diseases and conditions. You may see a cardiologist if you have coronary heart disease (CHD) or coronary microvascular disease (MVD).
- A vascular specialist. This is a doctor who specializes in diagnosing and treating blood vessel problems. You may see a vascular specialist if you have peripheral arterial disease (P.A.D.).
- A neurologist. This is a doctor who specializes in diagnosing and treating nervous system disorders. You may see a neurologist if you’ve had a stroke due to carotid artery disease.
Physical ExamDuring the physical exam, your doctor may listen to your arteries for an abnormal whooshing sound called a bruit (broo-E). Your doctor can hear a bruit when placing a stethoscope over an affected artery. A bruit may indicate poor blood flow due to plaque buildup.
Your doctor also may check to see whether any of your pulses (for example, in the leg or foot) are weak or absent. A weak or absent pulse can be a sign of a blocked artery.
Diagnostic TestsYour doctor may recommend one or more tests to diagnose atherosclerosis. These tests also can help your doctor learn the extent of your disease and plan the best treatment.
Blood TestsBlood tests check the levels of certain fats, cholesterol, sugar, and proteins in your blood. Abnormal levels may be a sign that you’re at risk for atherosclerosis.
EKG (Electrocardiogram)An EKG is a simple, painless test that detects and records the heart’s electrical activity. The test shows how fast the heart is beating and its rhythm (steady or irregular). An EKG also records the strength and timing of electrical signals as they pass through each part of the heart.
An EKG can show evidence of heart damage due to CHD and signs of a previous or current heart attack.
Chest X RayA chest x ray takes pictures of the organs and structures inside your chest, such as your heart, lungs, and blood vessels. A chest x ray can reveal signs of heart failure.
Ankle/Brachial IndexThis test compares the blood pressure in your ankle with the blood pressure in your arm to see how well your blood is flowing. This test can help diagnose P.A.D.
EchocardiographyEchocardiography (echo) uses sound waves to create a moving picture of your heart. The test provides information about the size and shape of your heart and how well your heart chambers and valves are working.
Echo also can identify areas of poor blood flow to the heart, areas of heart muscle that aren’t contracting normally, and previous injury to the heart muscle caused by poor blood flow
Computed Tomography ScanA computed tomography (CT) scan creates computer-generated pictures of the heart, brain, or other areas of the body. The test often can show hardening and narrowing of large arteries.
A CT scan also can show whether calcium has built up in the walls of the coronary (heart) arteries. This may be an early sign of CHD.
Stress TestingDuring stress testing, you exercise (or are given medicine if you are unable to exercise) to make your heart work hard and beat fast while heart tests are done.
When your heart is working hard and beating fast, it needs more blood and oxygen. Plaque-narrowed arteries can’t supply enough oxygen-rich blood to meet your heart’s needs.
A stress test can show possible signs and symptoms of CHD, such as:
- Abnormal changes in your heart rate or blood pressure
- Shortness of breath or chest pain
- Abnormal changes in your heart rhythm or your heart’s electrical activity
Computed Tomography ScanAngiography (an-jee-OG-ra-fee) is a test that uses dye and special x rays to show the insides of your arteries. This test can show whether plaque is blocking your arteries and how severe the blockage is.
A thin, flexible tube called a catheter is put into a blood vessel in your arm, groin (upper thigh), or neck. A dye that can be seen on x ray is then injected through the catheter into the arteries. By looking at the x-ray picture, your doctor can see the flow of blood through your arteries.
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Taking action to control your risk factors can help prevent or delay atherosclerosis and its related diseases. Your risk of atherosclerosis increases with the number of risk factors you have.
One step you can take is to adopt a healthy lifestyle. Following a healthy diet is an important part of a healthy lifestyle.
A healthy diet includes a variety of fruits, vegetables, and whole grains. It also includes lean meats, poultry, fish, beans, and fat-free or low-fat milk or milk products. A healthy diet is low in saturated fat, trans fat, cholesterol, sodium (salt), and added sugar.
The National Heart, Lung, and Blood Institute’s (NHLBI’s) Therapeutic Lifestyle Changes (TLC) and Dietary Approaches to Stop Hypertension (DASH) are two programs that promote healthy eating.
If you’re overweight or obese, work with your doctor to create a reasonable weight-loss plan. Controlling your weight helps you control atherosclerosis risk factors.
Try to do physical activity regularly. Physical activity can improve your fitness level and your health. Talk to your doctor about what types of activity are safe for you.
If you smoke, quit. Smoking can damage and tighten blood vessels and raise your risk for atherosclerosis. Talk to your doctor about programs and products that can help you quit. Also, try to avoid secondhand smoke.
Know your family history of atherosclerosis. If you or someone in your family has an atherosclerosis-related disease, be sure to tell your doctor.
If lifestyle changes aren’t enough, you also may need medicines to control your atherosclerosis risk factors. Take all of your medicines as prescribed.
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Causes | Risk Factors | Signs and Symptoms | Diagnosis | Prevention