High blood pressure is a condition in which blood makes pressure on artery walls. It usually has no obvious symptoms, unless it is very high, and the only way to find out if high blood pressure is present is to measure it.
Arteriosclerosis is a condition in which blood vessels become thin and stiff. Atherosclerosis is a condition in which cholesterol, fats, and other substances build plaque inside the arteries. In both cases, blood flow is affected.