They always use sleeping bags attached to the wall so that they do not bang into each other so that they go to sleep knowing they will wake up in the same place!
From time to time, some space travelers feel ill. About half of all astronauts suffer from space sickness for the first few days.
Astronauts in space also look different. More blood than usual goes to the head which makes their face fuller and fatter. Regular exercise is very important all the time as muscles can weaken.