Hi Daughter,
Arteries become blocked when you have a lesion on the artery wall that causes plaque formation leading to the narrowing and eventual blockage of the artery. One step that leads to the formation of lesions is the deposit of cholesterol along artery walls.
Here's a link to guidelines for treating clogged arteries:
http://www.healthscout.com/news/1/622869/main.html
All the best,
Lisa Nelson RD
How to Lower Cholesterol in 8 Simple Steps