What are the effects and symptoms of high cholesterol levels?

Atherosclerosis and. Asympotmatic. High cholesterol, by itself, does not produce any symptoms. It is a risk factor for atherosclerosis of blood vessels that can cause many diseases, e.g., heart attack, stroke, gangrene, kidney failure etc.
LDL, not Cholesterol. It have been known, for over 7 decades, that artery disease typically begins ~age 7, yet remains asymptomatic for decades; artery walls thicken & enlarge, not narrow. Events, including stenosis (narrowing), result from plaque rupture & clots. Optimize NMR particle test (hdl & LDL concentration, not cholesterol), keep hba1c low, optional ?5.0%, sbp ?120 mmhg, don’t smoke, exercise, avoid sugar, etc.