I need to know wat happened to my father?

my father cam back frm bangladesh 2 days ago he changed completely lik he luks more thinner i mean he was fat but when u luk at him u can say tat he lost a lot of weight he uses tha toilet frequently drinks a lot of water n food i mean eatin a lot very tired he doesn't luk healthy n even he doesn't know wat happened to him can any1 sugest wat it it my mom says tat he might got diabeties o remember he is arund 55