Venous insufficiency is one of the most important factors in understanding what can cause spider veins, reticular veins, and varicose veins. In the legs, blood returns from the legs to the heart via large veins. The job of these vessels is to transport blood against gravity all the way to the heart so the blood can receive oxygen and circulate again through the body. Veins do this through a series of one way valves located within them. Muscles from the leg act as a pump to push the blood upwards, and the valves prevent the blood from leaking back towards the feet.

What is venous insufficiency?

varicose vein valves

In many people, however, the veins' valves stop working. We are not sure exactly why this happens. But many risk factors for developing venous insufficiency work together to contribute to the appearance of varicose veins, spider veins, and other symptoms of venous disorders. These include:


  • Obesity
  • Hormonal changes (like pregnancy)
  • Trauma (breaking a leg or surgery on a knee for example)
  • Genetics (did any relatives have varicose veins?)

Venous insufficiency symptoms

Once the vein valves stop working correctly, they begin leaking blood back towards the feet, resulting in increased pressure. This often causes symptoms like swelling and achiness initially. If it persists, the branches of the poorly functioning veins start enlarging and becoming more visible in the leg. This can result in one or more of these visible symptoms:





It is important to realize that varicose veins, spider veins, and reticular veins do not happen for no reason. They happen because veins in the lower leg are functioning poorly and may need to be treated.