Illustrated by Anna Sudit.
What causes varicose veins?
“Veins are designed to bring blood back to the heart and lungs,” Dr. Green says. “To fight gravity, there are valves in the veins that fight the backflow of blood.” If the valves become weakened or the vein walls lose their shape, the blood flows back to the feet. The turbulence of blood flowing through the veins can cause swelling and change their shapes.
“In addition, your skin becomes thinner and weaker over time, so veins become more visible through the skin,” says Jessica Wu
, MD, a Los Angeles dermatologist. That goes for all veins, not just varicose ones.
While the natural course of ageing is a culprit, other factors can cause varicose veins. Look to your relatives to see if the condition is part of your family tree. “Both spider veins and varicose veins tend to run in families,” Dr. Gross says. If your mum and grandma have them, odds are your DNA has predisposed you to weaker veins. Thanks, genetics!
Oestrogen also plays a role. “Hormones seem to be connected to varicose veins, with oestrogen especially being linked to spider veins,” Dr. Gross says. “That’s why you tend to start seeing varicose veins as early as your teens — oestrogen levels are higher in your reproductive years.”
Pregnancy can also be the source of varicose veins, due to increased oestrogen levels. In addition, the weight of the baby inhibits circulation, making it difficult for the blood to flow back to the heart. As a result, blood pressure builds up in the legs, causing it to pool in the veins and weaken the valves.
Standing for extended periods of time — for work or during a sport — stresses the blood vessels because they have to fight gravity as long as you’re upright. Sitting too long can also cause blood to pool in the legs.
Spider veins in the face tend to have different causes. They’re often a result of rosacea due to the repeated flushing associated with the condition. Aggressive scrubbing or exfoliation can cause capillaries to burst. And, repeated sun exposure damages capillaries over time. Spider veins can also be associated with alcohol consumption since drinking causes high blood pressure that can dilate blood vessels.