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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.
Varicose veins often run in families. You may be born with defective valves or weak walls in your veins, or you may develop them later in life.
Varicose veins are more common in women than in men. And they happen more often as people get older.
Varicose veins often form during pregnancy. They might become less prominent after pregnancy and may disappear completely.
Clinical trials are research studies that evaluate a new medical approach, device, drug, or other treatment. As a Stanford Health Care patient, you may have access to the latest, advanced clinical trials.
Open trials refer to studies currently accepting participants. Closed trials are not currently enrolling, but may open in the future.