Large varicose veins that are near the surface of the skin can cause the skin to become very thin. If these veins happen to be bumped or cut it can cause the veins to bleed. The bleeding may be difficult to stop.
You should lie down, apply a pressure dressing to the area and elevate your leg for at least 20-30 minutes. Leave the pressure dressing in place for several hours before attempting to removing it. You may not be able to control the bleeding so medical attention may be needed. These bleeding veins may need to be injected or removed to prevent this from happening again.