By Macaela Mackenzie

Does it actually give you varicose veins?

If The Princess Diaries is to be taken seriously, a proper lady never crosses her legs at the knee. But other than trying to uphold as regal a posture as possible, there are a lot of scary medical rumours floating around about why crossing your legs is a definite don’t.
Is there any actual science behind the idea that sitting with your legs crossed can be bad for your health, though? Here’s what you need to know.
Varicose veins (and the achy, throbbing pain that tends to come with them) are often associated with sitting cross-legged – but this is a total wives’ tale, says John Harris, a vascular surgeon. (To prevent them, you should quit worrying about how you sit – instead, get “regular exercise, avoid long periods of leg dependency, and pick your parents well, as varicose veins are hereditary,” says Harris.)
What about other issues like nerve damage, high blood pressure and poor posture, which are sometimes linked to this particular way of sitting? It turns out, there is some evidence that sitting with your legs crossed can cause these issues. But before you panic, know that the effects are mostly temporary.
Your foot may fall asleep, but there’s no cause to worry about more serious nerve damage. When you cross your legs, you put pressure on the peroneal nerve, which is located behind the knee and supplies the sensation to your legs and feet. As soon as you uncross, the pressure is relieved and things go back to normal.
Research in the Journal of Clinical Nursing links crossed legs to high blood pressure. But while sitting this way does cause a spike in blood pressure, again, this returns to normal as soon as you uncross your legs. Still, you obviously don’t want to pump up your blood pressure for hours on end, so if you do default to sitting this way, make sure you’re at least getting up to stretch or walk around every 15 to 20 minutes.
Finally, there’s the concern that sitting with your legs crossed all the time can seriously mess up your posture (which in turn can screw with everything from your digestive system to your stress levels). This one is partially true.
If you make sure to sit straight, there won’t be any adverse posture effects, but the problem is, crossing our legs tends to make most of us slouch more. So long, perfect posture.
The bottom line: Crossing at the knees won’t kill you – just make sure you’re taking breaks to stretch out.