Question: Does standing upside down affect our circulation?

Reka Nagy answered on 18 Nov 2016:

Yes – if we do it on Earth! Gravity pulls our blood towards whatever part of our body is lowest, which is why your face starts to go red when you are standing upside down.

In space it’s a bit different – there is no gravity at all so there is no gradient of blood pressure that is lowest in your head and highest in your feet, as it is all even across your whole body. This is why astronauts have puffier-looking faces!