What is atherosclerosis?

Atherosclerosis (say: “ath-er-o-skler-o-sis”) is a disease that causes your arteries to become hard and narrowed. It’s even possible for an artery to become completely blocked. Your arteries are blood vessels that carry blood from your heart to the rest of your body.

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Causes & Risk Factors

What causes atherosclerosis?

Doctors don’t know exactly what causes atherosclerosis. It may first develop when the inner layers of your arteries become damaged. Many things can cause this damage, including:

  • High blood pressure
  • High cholesterol
  • Diabetes
  • Overweight or obesity
  • Smoking and tobacco use
  • Unhealthy diet
  • Lack of exercise
  • Family history of heart disease

When damage occurs, your body tries to repair your arteries. The repair process creates plaque (say: “plak”) deposits in the walls of the arteries. Plaque is made of fat, cholesterol, calcium, and other things that are naturally found in your blood. Over time, this plaque builds up in your arteries, becomes hard and makes your arteries narrow.

How do my cholesterol levels contribute to atherosclerosis?

High cholesterol can increase your risk for atherosclerosis. Cholesterol is a waxy substance your body uses to protect nerves, make cell tissues and produce certain hormones. Some cholesterol is essential for health.

Your liver can make all the cholesterol your body needs. Your body also gets cholesterol directly from the food you eat (such as eggs, meats and dairy products).

There are 2 important types of cholesterol to know about: low-density lipoprotein (LDL), or “bad” cholesterol, and high-density lipoprotein (HDL), or “good” cholesterol. LDL cholesterol is the type of cholesterol found in plaque. High levels of LDL cholesterol can damage your arteries and contribute to atherosclerosis. However, a high level of HDL cholesterol can actually help protect your arteries and prevent atherosclerosis.


How does atherosclerosis affect my body?

Atherosclerosis is the primary cause of cardiovascular disease. Cardiovascular disease is the leading cause of death in the United States. Types of cardiovascular disease include:

  • Coronary artery disease:Coronary artery disease occurs when plaque builds up in the arteries that supply blood to your heart. When blood flow to your heart muscle slows or when the arteries become blocked, it can cause chest pain and heart attack.
  • Small vessel disease:Small vessel disease occurs when plaque builds up in the small blood vessels of your heart. This can weaken your heart and cause chest pain, especially during exercise.
  • Stroke:A stroke occurs when an artery that carries blood to your brain becomes blocked. This can cause temporary or permanent brain damage, and you may lose the ability to see, speak or to move parts of your body.
  • Peripheral arterial disease (PAD):PAD occurs when plaque builds up in the arteries that supply blood to your arms or legs. This can cause numbness, pain and possibly infection in your affected limb(s).


How can I prevent atherosclerosis?

You can help prevent atherosclerosis by making lifestyle changes. The following lifestyle changes will reduce your risk of atherosclerosis by helping you lose weight, lower LDL cholesterol and increase HDL cholesterol levels, lower blood pressure and control your blood sugar (important if you have diabetes).

  • Exercise.Exercise can help you lose weight if you’re overweight or obese and also helps raise your HDL and lower your LDL cholesterol levels. Try to work up to 30 minutes of moderate-level activity, 4 to 6 times a week. Make sure you talk to your doctor before starting an exercise plan.
  • Quit smoking.Smoking can damage your blood vessels, reduce the flow of blood through blood vessels, and lower your HDL cholesterol levels. Even exposure to second-hand smoke can affect your blood vessels and cholesterol. Talk to your doctor about developing a plan to help you stop smoking.
  • Eat a heart-healthy diet.A heart-healthy diet includes a variety of fresh fruits and vegetables, whole grains, lean meats and “good” fats. See”High Cholesterol”  for more on eating a heart-healthy diet.
  • Talk to your doctor about adding supplements to your diet.Certain supplements may help improve your cholesterol levels if changing your diet isn’t enough. Some examples include:
  • Plant sterols and stanols.Plant sterols and stanols can help keep your body from absorbing cholesterol. Sterols have been added to some foods, including margarines and spreads, orange juice and yogurt. You can also find sterols and stanols in some dietary supplements.
  • Omega-3 fatty acids.If you have heart disease or high cholesterol, consider taking an omega-3 supplement. There are many types of omega-3 fatty acids, but the 3 main types are EPA, DHA and ALA. The most common and effective omega-3 fatty acid supplement is fish oil. A fish oil supplement should contain at least 1,000 mg of EPA and DHA (these are the specific omega-3 fatty acids found in fish). Vegetarians may prefer to get their omega-3 fatty acids from plant sources. For vegetarians, flaxseed oil is a common source of ALA, although ALA may not be as beneficial for heart health as EPA and DHA.
  • Red yeast rice. A common seasoning in Asian countries, red yeast rice may help reduce the amount of cholesterol your body makes. It is available as a dietary supplement. Talk to your doctor before taking red yeast rice, especially if you take another cholesterol-lowering medicine called a statin. The recommended dose of red yeast rice is 1,200 milligrams twice a day.
  • Manage stress.Try to reduce your stress levels. Ways to deal with stress include deep breathing and relaxation techniques such as meditation, gentle exercise such as walking or yoga, and talking with a friend, family member or health care provider about your problems.

What happens if lifestyle changes aren’t enough?

Your doctor may prescribe medicines to lower your blood pressure or cholesterol levels and to prevent blood clots. If you have severe atherosclerosis or have been diagnosed with cardiovascular disease, your doctor may recommend a procedure or surgery to open or bypass your blocked arteries.

Other Organizations


Questions to Ask Your Doctor

  • Am I at risk for atherosclerosis?
  • What is the likely cause of my atherosclerosis?
  • What changes can I make to reduce my risk?
  • How does my diet contribute to atherosclerosis?
  • Do I have high cholesterol?
  • How extensive is the buildup in my blood vessels?
  • Do I need any tests?
  • Am I at risk for heart attack or other complications?
  • Do I need medicine? Surgery?

American Heart Association. Cardiovascular disease statistics. Accessed 10/20/10

American Heart Association. Lifestyle changes and cholesterol. Accessed 10/20/10

Fish consumption, fish oil, omega-3 fatty acids, and cardiovascular disease by Kris-Etherton PM, Harris WS and Appel LJ(Circulation 2002;106;2747-57 ,http://circ.ahajournals.org/cgi/content/full/106/21/2747  )

Mayo Foundation for Medical Education and Research. Arteriosclerosis/atherosclerosis. Accessed 10/20/10

Mayo Foundation for Medical Education and Research. Cholesterol: Top 5 foods to lower your numbers. Accessed 10/20/10

National Heart, Lung and Blood Institute (NHLBI). Atherosclerosis. Accessed 10/20/10

National Heart, Lung and Blood Institute (NHLBI). Therapeutic Lifestyle Changes (TLC) section. Accessed 10/20/10