Atherosclerosis is responsible for most cardiovascular disease.
It is useful to compare atherosclerosis to what happens to a waterpipe over time. Rust and sediment from the water can begin to collect along the inside surface of the water pipe. Gradually the inside surface of the pipe, which was once smooth, becomes rough and begins to narrow. The flow of water may eventually be reduced to a thin stream and one day the waterflow may be blocked completely. Just like the water pipe, the inner walls of your arteries start out smooth so that the blood can flow through them easily.