Varicose veins

Skip Navigation
External view of legs with and without varicose veins, with details of healthy vein and twising varicose veins

Varicose veins are caused by weakened valves and veins in your legs. Normally, one-way valves in your veins keep blood flowing from your legs up toward your heart. When these valves don't work as they should, blood collects in your legs, and pressure builds up. The veins become weak, large, and twisted.

Current as of: August 6, 2023

Author: Healthwise Staff
Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.