We know that if people are not used to using any caffeine, and they start to use caffeine, their blood pressure goes up substantially. Within a week of caffeine consumption, however, we see that the effect is less pronounced—there is less of an increase in blood pressure. After several weeks of continued caffeine consumption, however, a little bit of increase in blood pressure remains. In studies that look at the incidence of hypertension in the general population, drinking caffeinated coffee is not associated with a substantial increase in risk. But if people have hypertension, and are having a hard time controlling their hypertension, they could try switching from caffeinated coffee to decaffeinated coffee, to see if it has a beneficial effect