Atherosclerosis is a condition in which fatty material collects along the walls of arteries. This fatty material thickens, hardens, and may eventually block the arteries.

Atherosclerosis is a type of arteriosclerosis. The two terms are often used to mean the same thing.

Atherosclerosis is a common disorder of the arteries. It occurs when fat, cholesterol, and other substances build up in the walls of arteries and form hard substances called plaque.

Eventually, the plaque deposits can make the artery narrow and less flexible. This makes it harder for blood to flow. If the coronary arteries become narrow, blood flow to the heart can slow down or stop, causing chest pain (stable angina), shortness of breath, heart attack, and other symptoms.

Pieces of plaque can break apart and move through the bloodstream. This is a common cause of heart attack and stroke. Blood clots can also form around the plaque deposits. Clots block blood flow. If the clot moves into the heart, lungs, or brain, it can cause a stroke, heart attack, or pulmonary embolism.

Risk factors for atherosclerosis include:

• Diabetes
• High blood pressure
• High cholesterol
• High-fat diet
• Obesity
• Personal or family history of heart disease
• Smoking

The following conditions have also been linked to atherosclerosis:

• Cerebrovascular disease
• Kidney disease involving dialysis
• Peripheral vascular disease

Symptoms usually do not occur until blood flow becomes slowed or blocked. If this happens, you may have chest pain or leg pain, depending on which artery is involved. Sometimes symptoms occur only with activity.

A health care provider will perform a physical exam and listen to the heart and lungs with a stethoscope. Early atherosclerosis can create a whooshing or blowing sound ("bruit") over an artery.

Tests that may be used to diagnose atherosclerosis or complications include:

• Ankle/brachial index (ABI)
• Arteriography
• Cardiac stress testing
• CT scan
• Doppler study
• Intravascular ultrasound (IVUS)
• Magnetic resonance arteriography (MRA)