What exactly are spider veins

Spider veins (also known as telangiectasias) are small “star” shaped bluish veins which are often found on the face and legs. Spider veins, unlike varicose veins, are very superficial and close to the skin surface. They are called spider because from the dark center of the vein are linear radiating smaller veins. Spider veins tend to be more prominent on the thigh, just below the knee and around the face. 

Spider veins are more often visible in light skinned people and appear to be more common in females. The smaller spider veins may resolve on their own but the majority persist and get darker. Spider veins never cause any symptoms and are of only a cosmetic concern.