Varicose Veins | Causes & Risk Factors


What causes varicose veins?

Veins return blood back to the heart so that it can be recirculated to the rest of your body. There are valves in your veins that open to allow the blood to flow towards the heart. In some people, the valves may stop working correctly, allowing blood to flow back down into the veins. (This often happens because the valves have stretched over the years.) Blood then pools in the veins, causing them to swell even more. The veins in your legs are especially vulnerable because those veins have to work against gravity to get the blood back to your heart. This is why most varicose veins are found in the legs.

This picture shows the difference between valves that work correctly (left) and valves that do not work correctly (right).

Risk factors for varicose veins include:

  • Genetics: Varicose veins tend to run in families.
  • Gender: Women are at greater risk of developing varicose veins.
  • Pregnancy: Hormonal changes, pressure from the uterus, and increased blood volume make varicose veins common during pregnancy.
  • Age: The risk for varicose veins increases with age. About 50% of people over the age of 50 have varicose veins.
  • Obesity: Being overweight puts additional pressure on your veins.
  • Job: If your work means you have to stand for long periods of time without moving around, you are more likely to get varicose veins.


See a list of resources used in the development of this information.

Written by editorial staff

Created: 05/10