Can you get sick easily in space?
-- Team Liberty Bell question

MAGNUS: Well, if you mean right away when you get there and you are trying to get used to zero gravity, I would have to say yes, you can. It is very important to move slowly as you are getting used to weightlessness and especially do not move your head too fast. Your inner ear, which helps you maintain balance on Earth, uses gravity to help it. Without gravity, your sense of balance from the inner ear gets messed up and your brain is trying to process these confused sensors along with what your eyes are sending back (there is no reference for up anymore!). After a few days, though, your body adapts and things are fine. Over the long term, it is possible to get sick, maybe like a cold or something, but it does not happen often. In order to stay on the ISS for a long period of time, we have to be in really good health. They are trying to minimize the possibility of a major medical problem occurring on the station because that would cause us to have to abandon the station and return home (for medical treatment). It turns out, though, that something about zero gravity causes a person's immune system to be depressed, so you are more susceptible to sickness. But since it is a closed loop system, you do not get new germs introduced so often.