Arteriosclerosis is a natural part of the aging process. Trouble is, our sometimes unhealthy lifestyles can accelerate it. Smoking and diabetes accelerate the process, among other things, I'm sure. It is also called hardening of the arteries. I call it *&^%$$%&&*!!!!
Our arteries (not veins) along with the force and frequency of our heatbeat, control our BP (along with the autonomic nervous system, and baroreceptors). As we age, or become diseased with arteriosclerosis, our arteries lose their elasticity. This results in general in our BP increasing. This is why some folks never need or take BP medicine until they are of some age.
When the heart beats (systole), the arteries expand to prevent our BP from increasing too much. When the heart is at rest (diastole) the arteries contract to keep our BP from going too low. So our arteries "buck" then "boost" our BP.
Then arteriosclerosis can contribute to blockages anywhere in our bodies. As the arteries become diseased, their shape can change and in general can lead to plaque buildup.
There is lots of info on the net about arteriosclerosis. The beginnings of this process can be seen during an eye exam. I was told years ago that I had arteriosclerosis, by my optician and ophthalmologist.