When I was younger and in better shape, the veins in my arms were very pronounced, a Phlebotomist’s dream I was told. Now I’m older and these veins are very difficult to draw blood from. At my suggestion, they usually have better luck with the veins on the back of my hands.
I assume that part of the problem might be that there’s more fat under my skin, but I wonder if my veins could have actually shrunk?
If so, could that shrinkage be an indicator of a health problem? I’ll ask my doctor next time, but I’m interested in what the TMs have to say.
I turn 65 in January.
Peace,
mangeorge
BTW; Two minute search wait, BIG improvement. 
From what I read, the elderly generally have small veins that are harder to hit. So I think it’s normal (though of course whether individual cases represent some kind of trouble I don’t know.
I can imagine that as one ages, and presumably does less strenuous work with the hands and arms, there’s a corresponding atrophy of the veins. More precisely, “work” increases the arterial inflow and thus demands a robust venous drainage system. In the absence of periods of increased arterial inflow, there’s no stimulus to maintain widely patent veins. Just a WAG mind you.
As I suspect you know, frequent blood letting and/or injections does cause the veins to become much more difficult to find and to get blood from once found. I don’t know the mechanism but perhaps it’s due the fact those things can lead eventually lead to occlusion of the target vein(s) and that, in turn, promotes its (their) atrophy. Truthfully, I’ve never wondered why - maybe after the holidays I’ll some vascular docs.
You may have hit an important reason right on the head when you mentioned accumulation of fat. That would certainly tend to mask and bury the veins.