Is it bad to cross your legs?!

Is it bad to cross your legs?

i have sat with my legs crossed probably starting when i was around seven now i am fourty. i cross them every time i sit down, eventually after a long priod of crossing my top leg gets numb. i have heard that crossing your legs can cause vein problems, back problems, and hip problems, i dont have any at all, but is this true that it is bad? do you cross your legs also? and are you aware it might be bad?

I'm 31 and I can not sit in a chair without crossing my legs. I can't sit on the floor without sitting Indian Style. I've heard the same things but I'm yet to have any problems myself.