Atherosclerosis is the build-up of fatty plaques inside artery walls that narrow and stiffen the arteries over years.
Early atherosclerosis is silent. Later, it can cause chest pain (heart arteries), leg pain on walking (leg arteries), TIAs or stroke (neck and brain arteries), or kidney problems, depending on which arteries are affected.
Imaging shows where plaques are, how much they narrow the artery, and which parts of the body are at risk of reduced blood flow.
Ultrasound (carotids, legs) shows plaque and flow; CT and MR angiography map the arteries in detail; coronary CT angiography assesses the heart arteries.
Treatment combines lifestyle change (stop smoking, exercise, diet), medications to lower cholesterol and control blood pressure, and procedures (angioplasty, stenting, bypass) for severe narrowing.
This entry explains the condition. The next step is having a radiologist interpret your specific scan, not a general definition.