What is the highest blood pressure reading that someone can have that doesn't increase risk for heart attack or stroke.

Blood Pressure: Blood pressure fluctuates widely and safely in most instances. Thus your question asking for a specific guideline is impossible to separate from the context that the heart is working in. What are your real concerns and symptoms?

Variable: But 140/80'is at the edge. Systolic 150 or more and diastolic 90'or more are concerning and anything systolic 180 or diastolic above 100 are quite dangerous i think.