One-Way Valves Weakened or Damaged
Veins have one-way valves to channel blood back to your heart. Spider veins, like varicose veins, can develop when the valves of your veins become weakened or damaged.
Cause of Weakness or Damage
- High blood pressure inside the superficial leg veins
- Standing for long periods of time
- Weakness in the walls of the veins
Blood Pooling in Veins Become Visible
When the valves become weakened or damaged, blood pools in the veins, enlarging them and often making the veins just below the skin visible. Spider veins can also develop when your veins are normal.