How high does a blood pressure go before it causes stroke?

What are the blood pressure risk levels?

Normal blood pressure is less than 120/80 mmHg
Uncontrolled high blood pressure is dangerous and can lead to stroke, heart failure, heart attack, kidney failure, and blindness.
You have prehypertension if your top (systolic) number is usually between 120 and 139, or your bottom (diastolic) number is usually between 80 and 89.
You have high blood pressure if your top (systolic) blood pressure number is usually 140 or higher, or your bottom (diastolic) number is usually 90 or higher. Both numbers are important.
If you have diabetes or chronic kidney disease, you have high blood pressure if your top number is usually 130 or higher, or your bottom number is usually 80 or higher.

Stroke also called: Brain attack , Strokes happen when blood flow to your brain stops. Within minutes, brain cells begin to die. There are two kinds of stroke. The more common kind, called ischemic stroke, is caused by a blood clot that blocks or plugs a blood vessel in the brain. The other kind, called hemorrhagic stroke, is caused by a blood vessel that breaks and bleeds into the brain. "Mini-strokes" or transient ischemic attacks (TIAs), occur when the blood supply to the brain is briefly interrupted.

Hope that'll help answer some of your questions...

Any time the systolic goes above 200 or the diastolic goes above 100 it's bad.
Blood pressure will differ from one person to another person, and it differs from time to time. More information available at http://ailments.in/hypertension.html...