Just before I started T I had some inexplicable rise in blood pressure. What was odd was that one GP said she was concerned, but several others didn't say that, and I got put on T anyway.
I was concerned about it myself, so as soon as I started HRT I stopped eating stuff with added salt, started drinking decaff only (eurgh) started drinking more water, and stopped eating as regularly or as much as usual, and started exercising more. Water fasting helps, as does weight loss.
This reminds me next time I get my blood taken this month I should ask for another BP reading, see if it's normalized.
For me, I can feel when the BP is higher, it's an uncomfortable sensation, as is water retention which T increases sometimes. One of the worst is the sensation of being aware of the blood in my neck veins when I'm trying to sleep, which sucks. But that's not been so bad since I started T actually. I think it is reducing.