Why It’s Common to Get Varicose Veins During Pregnancy

By Marisa Cohen
Reviewed by Alyssa Quimby, M.D.
January 04, 2023

At some point in your pregnancy, you may glance down and notice purple or blue lines running up and down your calves. These are known as varicose veins, and they appear on up to half of pregnant people.

“Varicose veins are dilated, long, twisting veins that usually appear in the lower extremities,” explains Alex Robles, M.D., a board-certified ob-gyn at Columbia University Irving Medical Center, in New York City. (According to Robles: When veins get swollen in your rectal area, they’re called hemorrhoids—another annoying side effect of pregnancy).

What Causes Varicose Veins?

Veins typically have a one-way valve that keeps the blood flowing upward against gravity toward the heart. But sometimes these valves can weaken and allow blood to back up, causing the veins to swell.