Spider Veins Underlying Cause
Veins are thin-walled vessels that carry oxygen-poor blood to the heart. Veins permit the flow of blood in one direction: back to the heart. Tiny valves inside the veins prevent blood flow from reversing direction. Working muscles help pump blood through the veins and back to the heart. Damage to valves in the leg veins causes blood to go the wrong direction and increases pressure in the lower leg veins. This causes the leg veins to bulge and prevents other valves from working normally.
Causes of varicose veins include:
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