Heart Health

What Is Atherosclerosis?

BY National Institutes of Health TIMEApril 13, 2022 PRINT

Atherosclerosis is a common condition that develops when a sticky substance called plaque builds up inside your arteries. Disease linked to atherosclerosis is the leading cause of death in the United States. About half of Americans between ages 45 and 84 have atherosclerosis and don’t know it.

Atherosclerosis develops slowly as cholesterol, fat, blood cells and other substances in your blood form plaque. When the plaque builds up, it causes your arteries to narrow. This reduces the supply of oxygen-rich blood to tissues of vital organs in the body.

Atherosclerosis diagram.
Normal artery and an artery with plaque buildup. (National Heart, Lung, and Blood Institute)

Atherosclerosis can affect most of the arteries in the body, including arteries in the heart, brain, arms, legs, pelvis, and kidneys. It has different names based on which arteries are affected.

Reduced blood flow can lead to symptoms such as angina. If a plaque bursts, a blood clots may form that may block the artery completely or travel to other parts of the body. Blockages, either complete or incomplete, can cause complications, including heart attackstrokevascular dementiaerectile dysfunction, or limb loss. Atherosclerosis can cause death and disability.

Confused About Terms?

Athero-sclerosis is not the same as arterio-sclerosis, which refers to “hardening of the arteries,” which means the arteries thicken and lose flexibility. Arteriosclerosis has several different causes. Atherosclerosis, which develops from fatty plaque buildup, is a common type of arteriosclerosis.

Plaque often starts to build up during childhood and gets worse with age. Risk factors include unhealthy cholesterol levels, unhealthy lifestyle habits, and your genes.

The good news is that most people can prevent or delay the initiation and progression of atherosclerosis by following steps for heart-healthy living.

Early stages of atherosclerosis often do not develop with symptoms. Symptoms may first appear when you’re under physical or emotional stress — times when the body needs more oxygen.

What Symptoms Does Atherosclerosis Cause?

Atherosclerosis leads to poor oxygen-rich blood supply, as well as symptoms that can affect your quality of life. Symptoms depend on which arteries are affected and how much blood flow is blocked.

  • Chest pain (angina), cold sweats, dizziness, extreme tiredness, heart palpitations (feeling that your heart is racing), shortness of breath, nausea and weakness are all symptoms of coronary heart disease.
  • Pain, aching, heaviness, or cramping in the legs when walking or climbing stairs are the main symptoms of peripheral artery disease. The symptoms also go away after rest.
  • Problems with thinking and memory, weakness or numbness on one side of the body or face, and vision trouble are all early symptoms of vertebral artery disease. Transient ischemic attack (TIA), commonly called a mini-stroke, is a more serious symptom.
  • Severe pain following meals, weight loss, and diarrhea are symptoms of mesenteric artery Ischemia of the intestines.
  • Erectile dysfunction (ED) is an early warning sign that a man may be at higher risk for atherosclerosis and its complications. If you have ED, talk with your healthcare team about your risk of plaque buildup,

You may not notice other symptoms until plaque buildup causes serious problems. Seeing your doctor regularly is important, as they may be able to find plaque buildup before it gets serious. For example:

  • Plaque buildup in the arteries of the neck (carotid artery disease) can cause a bruit. This is a whooshing sound that your doctor hears when using a stethoscope. Severe symptoms of a bruit include a transient ischemic attack (TIA).
  • Using a stethoscope, doctors may hear a bruit in your belly, which is an early sign of plaque buildup in the arteries that deliver blood to the kidneys (renal artery stenosis). As the disease worsens, it can cause high blood pressure, extreme tiredness, loss of appetite, nausea (feeling sick to the stomach), swelling in the hands or feet, and itchiness or numbness.

To diagnose atherosclerosis, your doctor will check the results of blood tests, imaging procedures, and other tests and also ask about your medical and family history. A physical exam helps detect symptoms.

Screening Tests

Beginning at age 20, your doctor will regularly check to see if you have risk factors for plaque buildup in the arteries. Your doctor may:

Estimating your Risk

Talk with your healthcare provider about risk factors:

  • Lifestyle habits, such as smoking or vaping, physical activity, and eating habits
  • Your personal health history, of medical conditions that may affect your risk, including diabetes and inflammatory conditions, such as rheumatoid arthritis and psoriasis
  • Your family history, if you have blood relatives who had heart attacks or died suddenly before they were 55 years old

risk estimator app can help assess the risk that you’ll have a major complication, such as a heart attack, from atherosclerosis. The app estimates your risk over the next 10 years or throughout your lifetime based on your data. If you have all the information, you can use the app yourself. The app shows risk levels as low, borderline, intermediate, or high.

Diagnostic Tests

To diagnose atherosclerosis, your doctor may order tests. Your doctor may recommend tests even if you do not have symptoms. The type of test depends on which arteries are affected by plaque buildup.

Blood Tests

Blood tests check the levels of cholesterol, triglycerides, blood sugar, lipoproteins, or proteins that are signs of inflammation, such as C-reactive protein.


An electrocardiogram, also called an ECG or EKG, is a simple, painless test that detects and records your heart’s electrical activity. An EKG can show how fast your heart is beating, whether the rhythm of your heartbeats is steady or irregular, and the strength and timing of the electrical impulses passing through each part of your heart. You may have an EKG as part of a routine exam to screen for heart disease.

An EKG may be recorded in a doctor’s office, an outpatient facility, in a hospital before major surgery, or as part of stress testing. For the test, you will lie still on a table. A nurse or technician will attach up to 12 electrodes to the skin on your chest, arms, and legs. Your skin may need to be shaved to help the electrodes stick. The electrodes are connected by wires to a machine that records your heart’s electrical activity on graph paper or on a computer. After the test, the electrodes will be removed.

An EKG has no serious risks. EKGs don’t give off electrical charges such as shocks. You may develop a slight rash where the electrodes were attached to your skin. This rash usually goes away on its own without treatment.

Heart Imaging Tests

Your doctor may order a heart imaging test to take pictures of your heart and find problems in blood flow in the heart or coronary arteries.

Examples of heart imaging tests used to diagnose atherosclerosis appear below.

  • Angiography is a special type of X-ray using a dye. This procedure can be used to check the arteries in the heart, neck, brain, or other areas of the body.
  • Cardiac MRI(magnetic resonance imaging) detects tissue damage or problems with blood flow in the heart or coronary arteries. Cardiac MRI can help explain results from other imaging tests such as chest X-rays and CT scans.
  • Cardiac positron emission tomography (PET) scanning assesses blood flow through the small blood vessels of the heart. This is a type of nuclear heart scan that can diagnose coronary microvascular disease.
  • Coronary computed tomographic (CT) angiography shows the insides of your coronary arteries rather than an invasive cardiac catheterization. It is a noninvasive imaging test using CT scanning.

Coronary Calcium Scan

A coronary calcium scan is a CT scan of your heart that measures the amount of calcium in the walls of your coronary arteries. Buildup of calcium, or calcifications, are a sign of atherosclerosis or coronary heart disease.

A coronary calcium scan may be done in a medical imaging facility or hospital. The test does not use contrast dye and will take about 10 to 15 minutes to complete. A coronary calcium scan uses a special scanner such as an electron beam CT or a multi-detector CT (MDCT) machine. An MDCT machine is a much faster CT scanner that makes high-quality pictures of the beating heart. A coronary calcium scan will determine an Agatston score that reflects the amount of calcium found in your coronary arteries. A score of zero is normal. In general, the higher your score, the more likely you are to have heart disease. If your score is high, your doctor may recommend more tests.

A coronary calcium scan has few risks. There is a slight risk of cancer, particularly in people younger than 40 years old. However, the amount of radiation from one test is similar to the amount of radiation you are naturally exposed to over one year. Talk to your doctor and the technicians performing the test about whether you are or could be pregnant.

Stress Tests

A stress test measures how healthy your heart is and how well it works during physical stress. Some heart problems are easier to identify when your heart is working hard to pump blood throughout your body, such as when you exercise.

You may do a stress test in your doctor’s office or a hospital. The test usually involves physical exercise such as walking on a treadmill or riding a stationary bicycle. If you are not able to exercise, your doctor will give you medicine that will make your heart work hard and beat faster, as if you were exercising. Your doctor may ask you not to take some of your prescription medicines or to avoid coffee, tea, or any drinks with caffeine on the day of your test, because these may affect your results. Your doctor will ask you to wear comfortable clothes and shoes for the test.

Ankle-Brachial Index (ABI) Test

Ankle-brachial index (ABI) tests are used to diagnose peripheral artery disease. This painless test compares the blood pressures in your ankle and your arm using a blood pressure cuff and ultrasound device.

Causes and Risk Factors

Risk factors are conditions or habits that make a person more likely to develop a disease. Nearly half of Americans have high blood pressure or unhealthy cholesterol levels, or they smoke. These are key risk factors that can trigger the start of plaque buildup.

What Causes Atherosclerosis?

Plaque buildup in the arteries starts with damage to the arteries. Risk factors such as unhealthy lifestyle habits, medical conditions, or your genes, can lead to this damage.

Inflammatory cells travel to the damaged areas of the artery and release chemical signals. The signals cause cholesterol and cell waste to collect at the damaged spots. This buildup attracts white blood cells that eat the cholesterol and clump together, forming plaque. The artery narrows as the plaque grows, reducing the flow of oxygen-rich blood to the limbs and organs. Over time, the plaque can break and flow into the bloodstream. This may lead to formation of blood clots, which can block blood flow. If this happens, nearby tissue can’t get enough oxygen and may die.

What Raises the Risk of Atherosclerosis?

The risk factors for plaque buildup are often linked. For example, smoking and a lack of regular physical activity raises your risk of unhealthy levels of cholesterol, which can lead to plaque buildup.

Other common risk factors for plaque buildup are listed below.

  • High blood pressure: Over time, high blood pressure can damage artery walls, allowing plaque to build up.
  • Diabetes: High blood sugar can damage the inner layers of the arteries, causing plaque buildup.
  • Metabolic syndrome: High levels of cholesterol and triglycerides in your blood increase your risk.
  • Unhealthy diet: Eating a lot of foods high in saturated fats can increase your cholesterol levels.
  • Family history: Your genes may increase your risk, especially if you have a common inherited cholesterol disorder called familial hypercholesterolemia.
  • Inflammatory diseases: When you have conditions such as rheumatoid arthritis and psoriasis, high levels of inflammation can end up irritating your blood vessels, which can lead to plaque buildup.
  • Older age: For most people, plaque buildup starts in childhood and gets worse as they get older. In men, the risk increases after age 45. In women, the risk increases after age 55. The risk for women is even higher if you have endometriosis or polycystic ovary syndrome, or if you had gestational diabetes or preeclampsia during pregnancy.

Source: National Heart, Lung, and Blood Institute; National Institutes of Health; U.S. Department of Health and Human Services.

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