Unrelated to topic but I was in hospital recently and nurses came around to do vital,blood pressure oxygen temperature.i was having a high blood pressure. Often I lay with crossed legs but a nurse told me to uncross my legs and blood pressure went down. Why why cross legs increase blood pressure ?
Ok I can kinda agree but I wasn’t cross legged. Just laying with right ankle on top of left ankle
I may be wrong, but I think holding a slightly cross legged position does still require some muscle contraction, and it may cause some compression over having your legs relaxed and spread apart. Also, if you’re lying on your back, then there might be a slight pressure difference from having one leg higher than the rest of your body.
The way you’re describing it, all of these factors will only change the pressure very slightly.
It could also be that you were more relaxed during the second reading, and so that time was the most important contributor. For example, white coat hypertension
https://en.wikipedia.org/wiki/White_coat_hypertension
When you cross your ankles, grab and feel your upper thighs. You’ll feel that they aren’t exactly relaxed and are somewhat contracting. Now feel them again when you uncross your ankles.