What Causes Spider Veins?

Skin Injuries

Some individuals have reported they developed spider veins after an injury or trauma to their skin. Skin injuries and leg injuries might damage the valves that control blood flow. Some individuals might only experience spider veins in the injured area. For others, the backflow of blood might lead other valves to become weaker, which in turn will cause spider veins to develop in other places in the legs or abdomen. Injuries might also make existing spider veins worse, though this isn't always the case. There are several different types of skin injury, and not every injury that might cause spider veins is severe. Tears, gashes, lacerations, and cuts are skin injuries that move through the skin to the fatty tissue underneath. Floor burns, scratches, abrasions, and scrapes are surface wounds and don't go all the way through the skin. Bruises are bleeding under the skin caused by damage to blood vessels. Surface abrasions are unlikely to contribute to spider veins unless they cause very unusual damage to blood vessel valves. Meanwhile, cuts and gashes deep enough to bleed are more likely to cause valve damage.