 Hey everyone! This week, three astronauts, Timothy Peake, Timothy Kopra and Yuri Malenchenko went into quarantine ahead of their trip to the International Space Station on December 15th. Once they arrive in space, their body will undergo numerous changes, the most obvious being a puffy face. So why do astronauts get puffy faces? We'll find out in today's space pod for December 2nd, 2015. On Earth, gravity moves our fluid down towards our legs. In space, that fluid is free to shift back up to our chest and head. To demonstrate how gravity can affect our bodily fluid, I'm going to deliver the rest of this space pod upside down. Watch the changes that happen to my face over time. Okay, so fluid shifts in space cause visual symptoms like a rounded puffy face and reddening of the skin. However, the fluid shift also causes your body to have more fluid in the chest and head than it's used to. It basically thinks that it's drowning. And to compensate for that, your body tries to excrete excess fluid to lower your blood volume. It does that by increasing urination and decreasing thirst. So as well as having too much fluid in your chest, your body also thinks it has too much fluid in your head. This can pool inside your sinuses and fill them up, leading astronauts to feel congested. This also affects their sense of taste. Have you ever noticed that your sense of taste changes when you have a cold? Well, it's like that for astronauts, except the change in taste doesn't last about a week or so, it lasts over their whole mission. This is why most astronauts prefer to eat spicier foods while in space because they can actually taste them. However, one of the worst symptoms of the fluid shift in space is an increase in intracranial pressure. That is the pressure inside of your skull. So this is believed to cause swelling of the optic nerve and a change in the pressure and shape of the eyeball. It's believed this may cause some of the vision problems that astronauts have when they go to space. And the worst thing is, when astronauts return home, sometimes those changes don't fix themselves. They're permanent. So because the fluid shifts towards the head and chest, this means that the fluid in the legs is reduced. This makes astronauts' legs look pretty skinny in space. And it's why Puffy Face Syndrome is affectionately referred to as Puffy Face Bird Leg Syndrome. Thank you for watching and I hope you enjoyed this space pod. And I hope you learned a little bit more about Puffy Face Bird Leg Syndrome than you knew before. If you liked this video, please subscribe to our YouTube channel at youtube.com. And consider sharing this video with your family and friends. If possible, also consider contributing to our Patreon campaign at patreon.com slash spacepod. We're actually already halfway to our next Patreon goal, which will see us delivering you spacepods once per week in 2016. Thank you to all our patrons who have helped us so far to bring you these spacepods. My name is Lisa Sturgeonoski and until next time, keep on discovering.