Why is atherosclerosis linked to high blood pressure?

Cause and effect but you can have either in spades w/out the other. Statistically they are linked.
Probably because high pressure damages the lining of the arteries and all major organs and their functions and atherosclerosis in turn raises BP.

Atherosclerosis or arteriosclerosis is a condition where plaque builds up on the walls of the blood vessels. This makes it harder to pump blood through the arteries, so the blood pressure rises to accommodate the hardened arteries. The two sort of go hand in hand.

Arthero means having to do with arteries.. when you have high blood pressure, you are continously putting stress on your arteries and therefore making them hard. So it's putting calcifications on your arteries.. which in turn make it hard to pump blood.

High blood pressure is not always the case. Atheriosclerosis is hardening of fatty deposits (plaque) in the arteries, causing restricted blood flow. I have had three angioplasties and have a stent and do not have a history of high blood pressure and not on medication for blood pressure. If you are asking this question due to a health issue for yourself, please see a doctor. If you are asking for knowing, there are hundreds of websites for your perusal.

Because the plaque that builds up on your ateries from bad cholesterol leads to atherosclerosis on the inside of your arteries, which then obviously narrows the areas in which your blood flows through. With that added resistance against the flow of you blood, you end up with a higher blood pressure.
Thats why you hear to watch your bad cholersterol....it can clog your arteries....give you high blood pressure....and you could end up with the big myocardial infarction (heart attack).

good luck to ya :)