Varicose veins

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: March 4, 2020

Author: Healthwise Staff
Medical Review: E. Gregory Thompson MD - Internal Medicine
Adam Husney MD - Family Medicine
Martin J. Gabica MD - Family Medicine