Jasmin, you also have to be sure that the device you use is precisely calibrated and that you are not the type that will have high anxiety if the initial reading is quite high. For example, if your basal BP is normally 145/95 and you suddenly see 155/110, it could enduce a state close to panic which will bump your BP even higher. The next thing you see is 170/115, your body is flooded with cortisol, and it's not going to come down--in time, perhaps, but not for hours in most cases.