Atherosclerosis is a disease where plaque builds up in the arteries, making them harder and narrower. It is caused by inflammation over time from risk factors like age, family history, obesity, lack of exercise, smoking, high blood pressure, and high cholesterol. Doctors use tests like angiograms to see blockages. Treatment focuses on managing contributing conditions with drugs or procedures like angioplasty and bypass surgery to reopen arteries. Prevention emphasizes lifestyle changes like a healthy diet, exercise, quitting smoking, and stress reduction.