Stress because you tighten up. Make a fist right now and you will see your veins tighten. that's because you are stretching the vein and it applies pressure to the below muscle making it visible.
It is just that mammary ducts are visible and may have been due to excessive breastfeeding.
the top side is normally brighter with semi-visible veins. the underside is normally darker with very visible veins.
The skull is in the way
Sore veins in your hand won't cause a disease.
If they're visible, they're near the surface, and probably are indeed warmer than surrounding tissue.
Dehidration is a major cause in sunken veins.
You should get your liver checked and drink less!
No. Many babies are born with visible veins.
according to my medical doctor, stress can cause hemroids to flare up. stress does not cause hemroids.
Penises become hard by inflating the organ with blood. This means that when large the veins in the penis are visible in may cases.
The overuse of a bone can cause a stress fracture.