Could this be a medical issue????? Please help!!!?

When I stand up any noises in the background fade in and out and there is a tightening feeling in my head. This happens whether I get up slow or fast. I don't feel like I am going to pass out nor am I dizzy. The same thing will happen if I stand too long in one place. Could I not have good blood circulation? I do have times when my blood pressure is high, but doctors aren't concerned since it goes up and down all the time. But this is happening more frequently and it is months before I can get into a doctor. I am not looking for a diagnosis, just wandering if this has happened to someone else and what caused yours? And no, I do not use any drugs to get this feeling.

BTW: I am a little overweight, borderline diabetic, and high cholesterol. I know I am a living timebomb, but try to keep everything under control.