Question: What is a normal blood pressure, and why is there controversy over the definition of 'normal' blood pressure?
Answer: So normal blood pressure, generally speaking, is 120 mm of mercury over 80 mm of mercury. So, top number 120, bottom number 80. The controversy really exists because blood pressure is sort of a moving target. I used to use the expression that it's like the stock market. You know, it goes up, it goes down.
It's been studied that actually the blood pressures are usually highest for most people in the early morning hours -- around 6 am -- and they slowly come down around until about noon. And then they start going up again until around 2 or 3 in the afternoon, and then come down around about 10 pm or so. And then this cycle sort of starts over again.
So in general, you really have to sort of find an average blood pressure of about 120/80, not just that one number.
Don't get fixated if the blood pressures are a little too high or if they're a little too low. You want to look at that mean average, or that average of about 120/80. That's the one that's associated with the lowest risk of stroke and heart attack.