The word is hella sick, it originated in Northern California in the bay area. Its used for hella things, you can use it for pretty much anything, just read the conversation:
Me: Dude, that party was hella sick last night.!
Tom: I know, there was hella people!
Me: I know you got hella drunk dude
Tom: I passed out hella early, when I woke up this morning I felt hella bad bro. I threw up hella times
Me: Dude you didn't even drink that much! I had hella beers and was up hella late!
Tom: Fuck you dude your hella annoying!