Leg-crossing causes varicose veins?

[snopes]

Comment: I have heard that crossing your legs while sitting aids in the
development of varicose veins. Is this true?

[Giselle]

Every pregnancy book I'm reading right now says so. I'm finding it an impossible habit to break.

[Artemis]

According to my Internet research, it's because of the increase of blood in the body when pregnant. Can't find anything about leg crossing.

[pirateslife]

I was told this in acting studio at Ole Miss. I stopped crossing my legs at the knees, which has at least kept them from going numb. It was a very hard habit to break. Occasionally, I now cross them at my ankles, like my high school always tried to get us young ladies to do. If only Mrs. Stanton had told us the varicose vein story, she might have been more successful.

pirates "Miss Penthouse '98, put your legs together! I could drive a boat show in there..." life

I don't think we can say that crossing your legs will definitely lead to varicose veins, but if you make a habit of it it may increase your chances of getting them. The best way to help the valves in the veins of your legs do their job is not to put pressure on them. Crossing your legs or sitting with your knees tucked up under you means that the valves are less efficient at transporting deoxygenated blood back up the leg to the heart, which can build pressure in the valves and cause damage.

ETA - Here is a good link explaining the known causes of varicose veins.

[Tantalus Prime]

My personal experience (not at all scientific) is that there is a strong genetic determinant to varicose veins. I have them. My father has them. So did his mother.

Mine started to appear around the age of 15 and now (33) they are getting to the point where I am considering surgery (they sometimes itch and can be uncomfortable, plus I am self-conscious about them). I can't imagine that at 15 I had crossed my legs so much as to cause varicose veins. When I went to see a specialist, I was told not only that it is was do to a leaky valve, but he also pinpointed which valve was the cause, near my pelvis not around the knees. I have heard about the leg crossing through hearsay, but not from any medical professional.

Another unusual thing (other than being a male with varicose veins) is that both I and my father have them on only one leg. Any one know if this is common?

[Buckle Up]

See, I knew there was another benefit to being overweight...I've always been too fat to cross my legs. Ha, ha, all you skinny women, my legs may be big, but they won't be all veiny and purple!

[Seraphina]

I do not know about varicose veins, but when i had a surgery I was not allowed to cross my legs, as it could reduce the blood flow and increase chance of blood clots. If the nurse noticed my legs cossed under the blankets she would come to tell me off. Also i believe that crossing your legs during flight can contribute to deep vein tromboses.

Varicose veins are caused by a failure in the system of valves keeping the blood flowing normally. When the blood stops flowing according to the circulatory system's design, gravity can take over and cause the blood to pool inside of the vein. Based on this, I would say that it is a reasonable assumption that if additional pressure is put on the veins by crossing the legs, it could damage the valves. This is only one possible cause of varicose veins. Other causes could be traumatic injury, pregnancy or even having a job that requires you to stand for long periods of time. More about varicose veins.