Subsequent to so many surgery a friend of mine veins are hard to find what can he do to make them show more?

Many causes.: The prominence of veins through the skin is affected by many factors including levels of hydration hormones, body temperature as well as outside temperature, medications and even levels of stress. Fair skinned people tend to have more easily visible veins than darker individuals and hereditary plays a strong role also. In a healthy person, visibility of veins is usually not of any concern.