What is Atherosclerosis?

What is Atherosclerosis?

Atherosclerosis is a common condition characterized by narrowing arteries and a reduced blood supply. This, in turn, leads to less oxygen carried to organs in the body. The narrowing of the arteries occurs gradually from cholesterol, fat, blood cells, and other substances in your blood that deposit in the inner walls of your arteries and form a plaque that grows and eventually may block your arteries. The blockage may not cause symptoms.

Lifestyle changes and medications may stop the development of plaque and prevent the risk of artery blockage in the heart and other parts of your body. Surgical procedures may be required in more advanced stages of the condition.

Atherosclerosis vs. Arteriosclerosis

Healthy coronary arteries are flexible and elastic, but the walls in your arteries can harden over time. This condition is called hardening of the arteries, or arteriosclerosis. Arteriosclerosis is a general term for several conditions with different causes. Atherosclerosis is a type of arteriosclerosis caused by the build-up of plaque. Even though atherosclerosis and arteriosclerosis are different, they are often used interchangeably. 

Stages of Atherosclerosis


Atherosclerosis, the narrowing of your arteries from plaque development, happens gradually over many years, often without symptoms. The stages of the condition describe the development of this plaque that leads to the arteries narrowing and, eventually, blockages.

H3: Stage 1: Initial damage 

Atherosclerosis begins with damage or injury to the endothelium, a thin lining of the inner layer of the artery. The cause of the initial damage may not be known and may happen in youth. Cholesterol, fat, and other substances in your blood may accumulate at the damaged site.

Stage 2: Fatty streak

A fatty streak is a yellow streak, or patch of dead macrophages, that starts accumulating at the artery-damaged site and the beginning of the plaque.

The damaged site may trigger an immune response and inflammation during this process. Macrophages, a type of white blood cell of the immune system, surround and kill pathogens (bacteria, viruses, and other microorganisms that cause disease), remove dead cells, and stimulate other immune system cells. In atherosclerosis, macrophages consume the cholesterol that starts to accumulate at the damaged site in your artery. When the macrophages die, the immune system in your body sends more white blood cells to the area, which further damages the endothelium. 

Stage 3: Plaque growth

The process continues, and the plaque at the site of the fatty streak grows and becomes harder. A layer forming on top of the plaque, called a fibrous cap, prevents pieces of plaque from breaking into the bloodstream. For a while, your artery wall can expand outward so blood can flow normally even while the plaque grows and starts blocking the artery so that you may have no symptoms. The plaque may stay stable for a long time, but eventually, there is insufficient space for the blood to flow.

Stage 4: Plaque rupture

The plaque continues to grow and narrow your artery, but the fibrous cap keeps it intact even as it grows. But if the fibrous cap breaks, pieces can enter the bloodstream, creating blood clots. Blood clots can block the blood flow and lead to a heart attack or stroke. The process is not fully understood yet and scientists are working to figure out why and how plaques rupture and who may be at risk.

Signs and Symptoms of Atherosclerosis


Early stages of atherosclerosis usually do not cause any symptoms. The plaque develops slowly, and often there may be no symptoms, even at a more advanced stage.

Symptoms of atherosclerosis depend on the affected artery or arteries and the level of their blockage.

  • Atherosclerosis of the heart arteries - chest pain or pressure (angina).
  • Atherosclerosis of the arteries leading to the brain
    • sudden numbness or weakness in your arms or legs
    • drooping muscles in your face
    • temporary loss of vision in one eye
    • difficulty speaking or slurred speech 
  • These are signals of a transient ischemic attack that require immediate treatment as it may lead to a stroke.
  • Atherosclerosis in the arms and legs arteries - leg pain or decreased blood pressure in an affected limb.
  • Atherosclerosis in the arteries leading to the kidneys - high blood pressure or kidney failure.

What causes Atherosclerosis?


The cause of atherosclerosis is unknown. It starts with damage or injury to the inner layer of an artery which may be caused by:

  • High blood pressure
  • High cholesterol
  • High triglycerides
  • Smoking 
  • Obesity 
  • Diabetes
  • Inflammation from diseases including arthritis, lupus, psoriasis or inflammatory bowel disease

Risk factors of Atherosclerosis

Risks Factors

Risk factors for developing atherosclerosis include:

  • Age. Atherosclerosis may start as early as in the teens or 20s and develops over time, often many years
  • High blood pressure can damage artery walls where plaque can start to build-up
  • High cholesterol and triglyceride levels contribute to plaque build-up
  • Diabetes
  • Obesity
  • Smoking 
  • Family history of early heart disease and inherited cholesterol disorder
  • Lack of exercise



You may not be able to prevent atherosclerosis, but you can take steps to reduce the risk of its advancement. Recommended healthy lifestyle changes include:

  • Avoiding or quitting smoking
  • Maintaining a healthy weight
  • Checking and maintaining a healthy blood pressure
  • Checking and maintaining healthy cholesterol level
  • Checking and maintaining healthy blood sugar level
  • Exercising regularly
  • Keeping a healthy diet
Get Care

Trust NewYork-Presbyterian for Atherosclerosis Care

At NewYork-Presbyterian, our expert cardiologists, surgeons, and other heart specialists collaborate to provide effective care to patients. Learn more about how atherosclerosis is treated, and about our approach to helping patients with coronary artery disease. Contact us to make an appointment.