Is your hypertension being treated? If so, you should be able to exercise normally. It's only if it's not being controlled that you need to worry. AND if you exercise, you should be able to come off the meds pretty easily (or at least in most cases this is true).
Now, if your BP is not controlled - get it controlled or wait for the meds to make it under control (usually takes very little time). Then keep an eye on it as you exercise, as your dosage will probably need to be lowered!
http://www.webmd.com/hypertension-hi...-exercise-tips