Have "a negative" blood type n have a vein q

Not sure if this should be posted in this particular forum, but since I have a- blood type, figured i'd try here. Is this normal?

i am 29 n have felt like i may have poor circulation for a while. when i hold my arm upwards, my veins appear normal n not enlarged.?

When my arms are to my side for example or held in a downwards position, my veins appear to enlarge. My arms can be compared with each other, if I do different positions for both. They have not always been like that, for just a few years they have. Is this a part of aging, or a problem? I've read that blood has to find a way to return upwards from certain positions. I don't always but I have had episodes of low blood pressure before. I've also had heart problems before even though dr's never diagnosed a heart attack. I had a dr say nothing happened when I had brachycardia n tachycardia occuring on the heart holter monitor info, and it listed brachycardia as occuring. I think she just didn't really read it. Should I be bothered by this? It even feels weird, not sure how much of it is my imagination worried because of how it appears. It quickly changes from normal to enlarged depending on positions. Like within less than a minute. I have had issues before where I couldn't feel my heart beating or pulse, n then other times where it was racing too fast, palpitations, skipping beats, severe chest pain. This has happened a lot. I used to be a smoker for over 10 yrs n quit a few yrs ago, permanently. I am not really sure when the vein stuff started though. Do you think it's normal for veins to be enlarging with position and then going back to normal size with another position? It just looks like that in my forearms n hands. I'd like to think I'm imagining it's worse looking than is. Tweet