This is kind of an ambiguous question with regards to what forum it might belong in, so I decided to put it into the most widely read one outside of the one that would bring some "don't put that question here" flames.
Anyway, I'm very curious as to what might effect vascularity not so much on the long term, but the short term, ie day to day or even hour to hour. As I understand it, it has a great deal to do with hydration, though that can not be the only component because I can be dead thirsty and have skimped on my water all day and display nice vascularity, while other times that same condition will leave my veins very well buried. It does appear that for myself, bodyheat plays an active role - when my temp is fairly elevated, they seem to pop. However, even this does not seem to be a constant. I'm just curious as I got out of the shower right now and my vascularity was the best it's been in months....despite my being sick all day yesterday and able to eat only three pieces of toast all day. Any thoughts??