Your body will rapidly develop tolerance for the blood pressure increase caused by many stimulants (caffeine, nicotine). You will likely see no more effect after just a few days.
I'm 26, I picked up smoking about 10 years ago (damn, that's a lot of time) and I have high blood pressure. That may also be due to genetic factors (both father, mother and grandmother with HBP).
While my BP is usually around 150/90, the three times I quit smoking for more than a week I return to normal values, around 120/80.
