What is atherosclerosis? Atherosclerosis is a condition in which circulating lipids, such as fats and cholesterol in the bloodstream, collect along the walls of arteries. This fatty material thickens and forms structures called plaques that narrow, and may eventually block blood flow through, the arteries. Large and medium-sized arteries are affected. Narrowing and blockage of arteries results in hypertension, chest pain, transient ischemic attack (TIA) or stroke, poor circulation to legs and feet, and other cardiovascular symptoms. Atherosclerosis is a common cardiovascular disease in the United States. The disease is a leading cause of illness and death in the United States. Atherosclerosis is the most common cause for heart attack and stroke. Most commonly, people develop atherosclerosis as a result of diabetes, genetic risk factors, high blood pressure, a high-fat diet, obesity, high blood cholesterol levels, and smoking. The signs and symptoms of atherosclerosis are usually not apparent until blood flow becomes restricted. The course of the disease varies among individuals. Some people with atherosclerosis have no symptoms at all, while others may have severe hypertension, aneurysm, blood clots, and coronary or peripheral artery disease. Fortunately, atherosclerosis can be treated successfully with medications, a healthy diet and lifestyle changes, and certain medical procedures. Even better, you can reduce your risk of atherosclerosis by following a heart-healthy diet, getting regular physical activity, and having regular checkups with your health care provider. Left untreated, atherosclerosis may lead to severe blood clots, which can cause stroke, heart attack, or pulmonary embolism. Seek immediate medical care (call 911) for serious symptoms, such as sweating and severe difficulty breathing, which may be combined with pale or blue lips, fast heart rate, chest pain or pressure, loss of consciousness, severe headache, or sudden numbness or weakness. Seek prompt medical care if you are being treated for atherosclerosis but mild symptoms recur or are persistent, such as leg pain or chest pressure.