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Last Updated: Mar 1, 2019


Atherosclerosis is a hardening of the arteries that results from a buildup of plaque. Plaque is made up of cholesterol, fat, calcium, clotting agents, cell debris, and other substances normally found in circulating blood. These substances accumulate at specific sites along the arteries and, over time, restrict or fully block blood flow to downstream organs, such as the heart, brain, and limbs. This process becomes accelerated when part of the plaque unexpectedly breaks off, or forms a blood clot.

Illustration of an artery cross section showing plaque

Depending on the location of the plaque and the extent of blockage, other complications may result. Plaque buildup in the coronary arteries, which deliver blood to the heart, can lead to coronary heart disease - the primary cause of deaths in the Untied States. Reduced or halted blood flow to the heart may cause a heart attack. Plaque in the carotid arteries (carotid artery disease), which deliver blood to the brain, can cause a stroke. A blockage in the major arteries (peripheral artery disease) causes pain and numbness in the limbs and pelvis, while blockage in the renal arteries (chronic kidney disease) affects kidney function. An aneurysm is a bulge in the artery wall that can be lethal if it bursts.

Atherosclerosis can be managed (and prevented) with lifestyle changes and medical intervention. Every year approximately 380,000 Americans die from coronary heart disease.

Causes and Risk Factors

Atherosclerosis can begin during childhood and progress slowly into adulthood. It is not clear what triggers the plaque-forming substances to deposit on the arteries, but damaged or scarred sites are thought to play a role. The following can damage the artery walls or promote plaque formation:


Atherosclerosis may not produce symptoms until it is at an advanced stage, at which time medical attention is needed. Symptoms vary depending on the affected artery.


common, external and internal carotid arteries

The first step in diagnosing atherosclerosis is a physical exam. During the exam, a doctor listens for abnormal sounds in the arteries and looks for a decreased pulse in the limbs, both of which are evidence of restricted blood flow. Additional tests are performed to assess heart function and gain a closer view of the arteries.


A combination of lifestyle changes, medication, and surgery may be used to treat atherosclerosis or slow its progression.


The best way to prevent atherosclerosis is by staying physically active, maintaining a healthy weight, and making smart food choices - that is, eating plenty of fruits and vegetables and avoiding foods high in cholesterol, fat and salt. It is also important to avoid smoking and stress-inducing activities. Individuals with a high risk of developing heart disease may consult their physician to determine the ideal preventative plan.


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Tina Shahian, PhD

Tina is a writer for Innerbody Research, where she has written a large body of informative guides about health conditions.


A communication specialist in life science and biotech subjects, Tina’s successful career is rooted in her ability to convey complex scientific topics to diverse audiences. Tina earned her PhD in Biochemistry from the University of California, San Francisco and her BS degree in Cell Biology from U.C. Davis. Tina Shahian’s Linkedin profile.


In her spare time, Tina enjoys drawing science-related cartoons.