Why is it important to my brain for me to avoid blood pressure extremes?

Extremes always bad.: The underlying problem in most diseases is too little or too much of something. (comment: it is true of political and religious belief systems--the extremes are wrong, harmful, dangerous). If BP is too low, all the organs of the body will be under-perfumed, but most sensitive will be the brain, where function very dependent on o2/glucose. Very high BP will lead to strokes, small & big. Control.