How much higher must your blood pressure get to compensate for a 5% narrowing in your blood vessels?

Using Bernoulli's fluid laws can someone explain this to me

"The pressure difference across your blood vessels is essentially equal to your blood pressure"

Po = ½ ρ (v1)²

I think I've plugged my numbers wrong I've come up with 23% and 5.25% and I don't know which is right.