Sometimes known as spider or broken veins, thread veins are small prominent veins that appear just below your skin surface, commonly on your face and legs. They tend to branch and give a spidery sort of pattern hence their common name. Thread veins are completely harmless.
A number of factors contribute to the appearance of thread veins on your skin, but they are all related fundamentally to placing pressure on capillaries and finer veins, resulting in damage or expansion. These factors include: genetic inheritance, ageing, sedentary lifestyle, sun-damage, obesity, alcohol, smoking and hormonal changes