I have swollen blood vessels when hands are hanging, if I hold them above the chest level, they look normal. Is it normal?

Probably. Blood pumped by the heart goes to the hand in arteries and comes back in the veins, which have no pump. Veins have a thin wall and are easily distended. Gravity pulls the blood down, distending the veins. Lifting the arms pulls blood back to the heart and the veins shrink. Further tests would be needed if arm elevation did not empty the veins.