This is also a good opportunity to discuss important travel health issues including safe food and water, accidents, sun exposure and insect bites. Many of the problems experienced by travellers cannot be prevented by vaccinations and other preventive measures need to be taken.
Age and genetics. As you get older, the veins in your hands may become more visible. Additionally, some peopleâs veins are naturally more visible. This could be due to skin pigmentation, body fat distribution, or a variety of other genetic factors. In most cases visible veins in hands are not a sign of a medical condition, or of any other problems.
A larger vein size makes it easier to donate plasma. But your vein size depends on how hydrated you are, what you've eaten that day, the phlebotomist, how much water you've drunk, your caffeine intake (caffeine can constrict your veins a bit,) and if you've worked out that morning.