Having a normal BP does NOT rule out a brain tumor; imaging that is normal does, i.e. a negative MRI.
...let's just say that if I had normal blood pressure (which I do)
...and, I experienced headaches and light-headedness (which I occasionally do)
...I wouldn't be thinking that I had a brain tumor.
...I'd be thinking that I'm either having an allergic or an adverse reaction to something that I'm breathing in or that I'm undergoing a moderate degree of stress.