Study permit status when taking a gap year due to illness

[yusan0]

Hi, I'm an international student studying full-time in university. I have to leave school due to illness, will this affect my study permit?
If I get my fall term off and become part-time student in the winter term (the schools say that leaving within three months will make me a part-time student), will this record affect me on applying working visa after graduate?
If I'm away for the whole Fall-Winter terms, do I have to reapply for study permit?
I really need someone's help, thanks!