You can lower your hypertension
with relaxation techniques
only if your hypertension is caused by stress
If it is of a clinical origin, then no.
Now, there are many causes of hypertension, such as:
drugs (prescribed ones, not the recreational type)
type 2 diabetes
As you might guess, using your mind in any of these situations will not help, for it is not the mind that causes teh hypertension.
A question: Why wouldn't you want to take medication for it? Hhypertension medication has been around for a very long time as these drugs go and have a very good track record. If you have hypertension I would strongly recommend that you take medication for it. The risks of having it far outweigh the risks of taking blood-presure medication.