At the American Society of Hypertension meeting, there was a presentation that showed that the caffeine in coffee produces an acute elevation in blood pressure in patients with a history of high blood pressure, but there does not appear to be a longer-term effect on blood pressure or cardiovascular risk, a systematic review and meta-analysis showed.
In a meta-analysis of five trials, consuming 200 to 300 milligrams of caffeine -- the amount found in one-and-a-half to two cups of coffee -- produced a mean increase in blood pressure of 8.1/5.6 mm Hg. The effect on the blood pressure was most pronounce from 1-3 hours after consuming the coffee.
The bottom line is that if you have high blood pressure and are a caffeinated coffee (or probably any caffeinated beverage) lover, you should check your blood pressure about 1-2 hours after drinking the caffeine. If you have high blood pressure that is not well controlled, then you might want to consider switching to decaf.
