No, you can never grow your veins back but you can get surgery and new veins can be put into your veins system.
P.S. My brother got a surgery. He is perfectly fine.
Ofcourse not, you don't see them, your fingernails can't bleed and the body doesn't see a need to put nerves in it.
anal
VEINS ~ It's Arteries OUT and Veins BACK
Veins take blood back to the heart.
veins take the CO2 back to the lungs as a waste.
veins
collateral veins are produced by your body when it thinks it is not getting sufficient circulation from a part of the body. If a part of your body is not returning blood back to the heart from a particular part of the body, your body will grow veins around that area to assisst in circulating the blood. Unfortunately these veins are usually thinner and less organized than the original venous structures. Spider veins are examples of collateral veins. There are collateral arteries as well. When a part of the body is not receiving enough oxygen new arteries will grow around to assisst in circulation. Like veins these are of poor structural quality too.
The pulmonary veins are veins which carry oxygenated blood (unlike most veins) back from the lungs to the left atrium of the heart.
Veins carry the blood back after it delivered the oxygen.
Veins
Veins
Veins have valves in them which help transport the blood.